1 to 25 of 39 Penetration Tester Jobs in London

A premier UK consultancy is seeking a skilled and passionate Penetration Tester to join its growing team of cybersecurity experts. This is a dynamic opportunity for individuals with strong technical skills and a proactive mindset, eager to make a tangible impact across a wide range of client environments. Working on mission critical projects across National Security, Critical National … Infrastructure and Defence the Senior Penetration Tester will liaise with highly-skilled teams acting as a trusted advisor. Key Responsibilities: Conduct hands-on internal penetration tests in infrastructure/Active Directory environments Produce clear and concise technical reports, summarising findings for both technical and business stakeholders Work directly with clients as a trusted advisor – this is a … also be available: Possesses industry-recognised certifications such as CTM, CSTM, CTL, CSTL, OSCP, or CREST/Cyber Scheme qualifications. Brings specialist knowledge in one or more areas of penetration testing – this could include mobile app security, cloud environments, operational technology (OT), or specific sectors such as telecommunications, defence, or maritime. Demonstrates a strong desire to contribute to the More ❯

A premier UK consultancy is seeking a skilled and passionate Penetration Tester to join its growing team of cybersecurity experts. This is a dynamic opportunity for individuals with strong technical skills and a proactive mindset, eager to make a tangible impact across a wide range of client environments. Working on mission critical projects across National Security, Critical National … Infrastructure and Defence the Senior Penetration Tester will liaise with highly-skilled teams acting as a trusted advisor. Key Responsibilities: Conduct hands-on internal penetration tests in infrastructure/Active Directory environments Produce clear and concise technical reports, summarising findings for both technical and business stakeholders Work directly with clients as a trusted advisor – this is a … also be available: Possesses industry-recognised certifications such as CTM, CSTM, CTL, CSTL, OSCP, or CREST/Cyber Scheme qualifications. Brings specialist knowledge in one or more areas of penetration testing – this could include mobile app security, cloud environments, operational technology (OT), or specific sectors such as telecommunications, defence, or maritime. Demonstrates a strong desire to contribute to the More ❯

CHECK Senior Infrastructure Penetration Tester PGI is a global consultancy that helps organisations build digital resilience. We deploy our people to implement solutions on behalf of clients or to support them in developing their capabilities. Our Penetration Testers work with organisations of all sizes and types to detect and remediate vulnerabilities. They help identify areas lacking sufficient … could exploit, and makes recommendations to safeguard assets. What you'll be doing: Providing professional cybersecurity consultancy to internal and external stakeholders. Leading the delivery of PGI's infrastructure penetration testing. Collaborating on the design and delivery of new and existing service lines related to offensive security assessments. Supporting and often leading technical pre-sales, proposal writing, and client … ensure successful outcomes. Mentoring security consultants or clients by sharing knowledge and overseeing skill development. Participating in exercises such as Capture The Flag (CTF) challenges. Providing accurate scoping of penetration testing opportunities for sales activities. Supporting sales activities with proposals and client presentations. Supporting marketing with subject matter expertise and content development. Developing and maintaining technical skills and certifications More ❯

Join our dynamic Offensive Security Team! As we expand, we are looking for a Pentester/Red Teamer who is enthusiastic about undertaking a range of security assessments, including penetration testing, red team exercises, vulnerability scanning, and physical access evaluations for our clients. Key Responsibilities: Client Engagement Management: Lead client projects, ensuring clear communication, timely delivery, and exceeding expectations. … Act as the primary liaison, providing updates and guidance. Security Assessment Execution: Conduct detailed security assessments, including penetration testing and vulnerability analysis. Systematically identify and document vulnerabilities across network, application, and physical layers. Prepare concise reports for both technical and non-technical stakeholders. Red Team Challenges: Participate in red team simulations, encompassing social engineering attacks and advanced penetration … security. Technical Proficiencies: Python/Scripting: Demonstrate a high level of proficiency in Python, essential for writing custom scripts to automate tasks, analyze data, and develop unique tools for penetration testing. This skill is crucial for tailoring attacks, parsing data, and creating efficient workflows in security assessments. Linux/Windows Proficiency: Have a thorough understanding of Linux/Windows More ❯

Senior Penetration Tester – Must be eligible to obtain security clearance We are looking for a Senior Penetration Tester/Ethical Hacker to work freelance for a company who delivers high-quality security solutions for an array of different clients from varied industries. Due to an unprecedented increase in workload, we are looking for a reliable Penetration Tester to work on overflow projects, delivering infrastructure penetration testing, including broader vulnerability assessments and security audits as needed. You will also produce clear, professional reports and deliver testing debriefs. This opportunity would suit someone who is already in a permanent position, looking for freelance work in addition to their main role, or someone who is happy … nature of work and client base, all applicants but be able to obtain SC clearance. Day rate: £400 - £500 per day, London – remote/hybrid Requirements Proven experience in Penetration Testing/Ethical Hacking Strong knowledge of network and cloud infrastructure security. Up-to-date on the latest cybersecurity threats and technologies. Strong knowledge in pen testing tools ( Metasploit More ❯

Security Testing Consultant (Pen Tester) Location: London SE1 Salary: £45,000 - £60,000 depending on relevant experience Hours: Full-time, Monday to Friday Work Location: Office-based during probation, then hybrid (3 days office/2 days WFH) Full time/Permanent Remarkable Jobs are recruiting on behalf of a dynamic and growing cybersecurity organisation. We are seeking a … Security Testing Consultant (Pen Tester) to join their expert team in London SE1. This is a fantastic opportunity for an experienced professional to take on a varied, high-impact role conducting in-depth security assessments across multiple platforms. Security Testing Consultant (Pen Tester) Role: As a Security Testing Consultant (Pen Tester) , you will play a vital role … platforms, APIs, and mobile technologies. You'll be part of a collaborative team, providing expert guidance and helping to ensure the highest standards of cybersecurity. Security Testing Consultant (Pen Tester) Key Responsibilities: Deliver penetration testing across web, cloud, mobile, and infrastructure Conduct black box, grey box, and white box testing Produce detailed reports and deliver findings to clients More ❯

Penetration Tester - Remote About the Role Lorien are seeking a talented and motivated Penetration Tester to join our clients growing cybersecurity team on a fully remote basis (mainland UK only). You will be responsible for conducting ethical hacking and security testing engagements to identify vulnerabilities in client systems, applications, and infrastructure. This is an exciting … opportunity to work across a range of industries while further developing your skills in a supportive and professional environment. Key Responsibilities Plan and perform penetration tests on networks, web applications, APIs, cloud environments, and other systems. Deliver clear, actionable technical and executive reports to clients. Collaborate with internal teams to ensure quality and compliance with best practices. Stay up … CCTIM Certified Must be currently residing in mainland UK . Eligible for UK security clearance (must have been a UK resident for at least 5 years). Experience conducting penetration tests (web, infrastructure, external/internal). Strong knowledge of security testing methodologies and frameworks (e.g., OWASP, NIST). Proficiency with industry-standard tools (e.g., Burp Suite, Nmap, Metasploit More ❯

Senior Penetration Tester – (UK only - Must be eligible for Security Clearance) Location: UK (Leeds, Bristol, London or Remote) Salary - £45k - £60k Step up your game in cybersecurity. We’re looking for an experienced Senior Penetration Tester who thrives on pushing boundaries, thinks like an attacker, and delivers like a pro. You’ll be joining a tight … knit team of passionate ethical hackers tackling high-impact, real-world cyber threats across both government and commercial landscapes. What You’ll Be Doing: Lead and deliver hands-on penetration tests Mentor junior testers and review technical outputs Collaborate with clients and provide expert guidance Feed into proposals and help shape strategic direction Continuously grow your technical and consulting … skills What You’ll Need: ✔ NCSC CHECK Team Member status ✔ Solid UK penetration testing experience (ideally across varied environments) ✔ Technical depth in networks, systems, and application testing ✔ Strong communication and reporting skills ✔ A hacker mindset and the drive to stay ahead of evolving threats ✔ Clear and demonstrable understanding of penetration testing and red-teaming including NCSC and CREST More ❯

Role: Penetration Tester (Infrastructure Focus) ️ Work Type & Location: Hybrid – London preferred (other UK cities possible) ️ Role Type: Permanent Salary: £70,000–£105,000 (London) depending on experience Other regional packages available for Cambridge, Manchester, Bristol, or Edinburgh Our client – a global innovation consultancy – is expanding its Digital & Data capability and is on the lookout for an experienced Penetration Tester (Infrastructure Focus) to join a high-trust, hands-on team. This role is all about deep technical work inside live infrastructure environments – think Active Directory, internal networks, and sensitive systems where precision matters. If you’re the kind of tester who thrives in complex, undocumented environments and enjoys real-world impact over checkbox testing, this is … the challenge for you. As a Penetration Tester (Infrastructure Focus), you will: Deliver internal infrastructure tests in high-risk, high-impact environments Focus on Active Directory, lateral movement, and privilege escalation techniques Communicate directly with clients to present findings and advise on remediation Produce clear, actionable reports for both technical and non-technical stakeholders Contribute to improving internal More ❯

has grown to employ elite technical experts who have contributed to some of the world's largest technology and digital security projects. The NCSC-approved CHECK company specializes in penetration testing and security assessment services under the government-accredited CHECK scheme. They are currently seeking for a skilled Penetration Tester to join the growing team. This role … standard and in-house developed tools for security testing. Conduct manual reviews to identify issues within customer infrastructure and web applications. Perform various types of security testing, including network penetration, web application, mobile security assessments, and social engineering. Participate in red team engagements, employing creative strategies to outsmart defenders. Explore various approaches to gain unauthorized access to customer networks … solving capabilities. Possesses a solid understanding and fascination with fundamental concepts in operating systems and networking. Displays a keen interest in security principles and protocols. Demonstrates proven experience in penetration testing and/or security surveillance. Exhibits eagerness to absorb new knowledge and technologies. Programming Exposure A relevant Cyber Security certification is advantageous, e.g. (OSCP, CRT, CTM, CTL) Showcases More ❯

range of areas including Risk Assessments, Vulnerability Management, Accreditations (ISO27001, GDPR), GRC (Governance, Risk, Compliance), Security Architecture Design and Build (technical and Non-technical), Incident Response, Protective Monitoring Services, Penetration Testing and much more. We take clients through a journey to improve their overall security posture and maturity to ensure they feel reassured in the Security control, measures and … go. Our roles are only available if you hold or fulfil the criteria to obtain a UK Security Clearance. Your future duties and responsibilities An opportunity for an experienced penetration testers has become available due to growth, joining the CGI Cyber Security business unit, one of the largest groups of cyber security specialists in the UK. CGI has a … years. Experience of the assessment of bespoke applications, cloud technologies and mobile applications (on diverse mobile platforms) would be of an advantage. You would join our established team of penetration testers with the possibility of progressing to team leader or principal tester positions. You would be able to work flexibly, undertaking work at home and at client sites More ❯

Penetration Tester – Infrastructure Salary: £70,000–£100,000 (depending on experience) Location: Hybrid – London (2 days per week on-site) Note: To be eligible for this role, you must be eligible for UK Security Clearance (SC). A high-performing digital security team is looking for an experienced Infrastructure Penetration Tester to join them in delivering … is suited to testers who thrive in technically demanding scenarios, want autonomy, and are motivated by work with real-world impact. Key Responsibilities Conduct internal infrastructure and Active Directory penetration tests in live production environments Produce clear, concise reports tailored to both technical and non-technical audiences Build trusted relationships with clients in a consultancy-facing capacity Work within … the evolution of internal tooling and testing methodologies Operate effectively in environments with limited documentation or predefined processes Essential Experience and Skills At least 4 years’ experience in infrastructure penetration testing Strong knowledge of Active Directory exploitation techniques (privilege escalation, lateral movement, etc.) Confident working in high-stakes, sensitive environments Strong command-line skills across Windows and Linux systems More ❯

Penetration Tester – Infrastructure Salary: £70,000–£100,000 (depending on experience) Location: Hybrid – London (2 days per week on-site) Note: To be eligible for this role, you must be eligible for UK Security Clearance (SC). A high-performing digital security team is looking for an experienced Infrastructure Penetration Tester to join them in delivering … is suited to testers who thrive in technically demanding scenarios, want autonomy, and are motivated by work with real-world impact. Key Responsibilities Conduct internal infrastructure and Active Directory penetration tests in live production environments Produce clear, concise reports tailored to both technical and non-technical audiences Build trusted relationships with clients in a consultancy-facing capacity Work within … the evolution of internal tooling and testing methodologies Operate effectively in environments with limited documentation or predefined processes Essential Experience and Skills At least 4 years’ experience in infrastructure penetration testing Strong knowledge of Active Directory exploitation techniques (privilege escalation, lateral movement, etc.) Confident working in high-stakes, sensitive environments Strong command-line skills across Windows and Linux systems More ❯

Penetration Tester – Infrastructure Salary: £70,000–£100,000 (depending on experience) Location: Hybrid – London (2 days per week on-site) Note: To be eligible for this role, you must be eligible for UK Security Clearance (SC). A high-performing digital security team is looking for an experienced Infrastructure Penetration Tester to join them in delivering … is suited to testers who thrive in technically demanding scenarios, want autonomy, and are motivated by work with real-world impact. Key Responsibilities Conduct internal infrastructure and Active Directory penetration tests in live production environments Produce clear, concise reports tailored to both technical and non-technical audiences Build trusted relationships with clients in a consultancy-facing capacity Work within … the evolution of internal tooling and testing methodologies Operate effectively in environments with limited documentation or predefined processes Essential Experience and Skills At least 4 years’ experience in infrastructure penetration testing Strong knowledge of Active Directory exploitation techniques (privilege escalation, lateral movement, etc.) Confident working in high-stakes, sensitive environments Strong command-line skills across Windows and Linux systems More ❯

Job Title: Penetration Tester Role: An exciting opportunity for a mid-level Penetration Tester to join a dynamic and collaborative security consultancy based in London. This role is ideal for a proactive individual with a hacker’s mindset and broad security testing experience across applications, networks, cloud platforms, and more. You'll be a key player … in delivering high-quality penetration tests while also supporting client advisory, team development, and process improvement. What’s in it for you? Autonomy and ownership in conducting diverse penetration testing engagements. Ongoing professional development with access to industry events and training. A positively charged work environment with flexibility for hybrid working post-probation. Responsibilities: Conduct web, mobile, API … infrastructure, cloud, and wireless penetration testing. Create detailed technical reports and deliver test findings directly to clients. Provide remediation advice and post-assessment consultancy. Contribute to internal testing methodologies and Red Team/social engineering activities. Mentor junior team members and support collaborative delivery of projects. Occasionally support the creation of marketing materials such as research papers and articles. More ❯

We are seeking a highly skilled and experienced Offensive Security Consultant with a strong focus on threat intelligence and attack methods. The ideal candidate will manage and conduct advanced penetration testing engagements, leveraging threat intelligence to simulate real-world attacks across various environments, including OT, IT, web applications, cloud infrastructure, and APIs. This role requires a deep understanding of … skills, and the ability to provide strategic, actionable recommendations to enhance our clients' security posture. What you'll be doing: Responsibilities: Lead and manage the full lifecycle of complex penetration testing engagements, applying a threat intelligence-led approach. Execute advanced penetration tests across environments such as applications, infrastructure, web, APIs, O365, Azure, AWS, and OT, using current threat … detection and response. Drive patching efforts for vulnerabilities based on threat intelligence and exploitation potential. What experience you'll bring: Skills and Qualifications: At least 5 years of professional penetration testing experience with a focus on adversarial tactics and threat intelligence. Understanding of OT and IT assets, technologies, and security best practices within the current threat landscape. Deep knowledge More ❯

Senior Penetration Tester – UK remote - £60,000 - £80,000 Opus are looking for an experienced Penetration Tester to join our client, a cyber consultancy specialising exclusively in penetration testing and red teaming, delivering high-impact, adversary-simulated engagements for clients ranging from agile tech scale-ups to critical infrastructure providers. As a Senior Penetration Tester, you’ll play a central role in executing and shaping these engagements—across infrastructure, web, cloud, and bespoke environments—while also leading goal-based assessments and full-scale red team operations. This is a hands-on, client-facing position suited to someone who thrives in technically demanding scenarios and wants to work alongside a small, elite team … of offensive security specialists. Key Responsibilities Lead and execute complex penetration tests and adversary simulations Deliver red team engagements aligned with frameworks like TIBER, CBEST, and MITRE ATT&CK Develop custom tooling and exploits where required Create detailed, client-facing technical and executive reports Mentor junior testers and contribute to internal R&D Support scoping, pre-engagement, and post More ❯

Penetration Tester – Infrastructure Focus 📍 Location: London preferred (Hybrid) 💸 Salary: £70,000 – £105,000 (London) 🧠 Level: Senior Consultant to Principal Consultant (SC–PC) ⏱ Flexible hybrid model | High-trust culture | Mission-critical work 🧭 The Opportunity Join a high-impact consultancy at the forefront of innovation and digital transformation. You’ll be part of a specialist team delivering critical infrastructure penetration … in the UK — from defence and national security to critical infrastructure and operational technology. This is not a web application role . We’re looking for an infrastructure-focused penetration tester with the technical confidence and consultancy mindset to work independently, lead engagements, and deliver real-world impact. If you want to push beyond checklists and automated scans … methodologies, and continuous improvement of team capability Engage with a technical and non-technical audience, acting as a trusted security advisor 🧠 What You Bring Core Skills: 4+ years of penetration testing experience (infrastructure/internal focus) Strong hands-on expertise with Active Directory attacks, lateral movement, and privilege escalation Experience navigating live and legacy production systems Comfortable in Windows More ❯

Penetration Tester – Infrastructure Focus 📍 Location: London preferred (Hybrid) 💸 Salary: £70,000 – £105,000 (London) 🧠 Level: Senior Consultant to Principal Consultant (SC–PC) ⏱ Flexible hybrid model | High-trust culture | Mission-critical work 🧭 The Opportunity Join a high-impact consultancy at the forefront of innovation and digital transformation. You’ll be part of a specialist team delivering critical infrastructure penetration … in the UK — from defence and national security to critical infrastructure and operational technology. This is not a web application role . We’re looking for an infrastructure-focused penetration tester with the technical confidence and consultancy mindset to work independently, lead engagements, and deliver real-world impact. If you want to push beyond checklists and automated scans … methodologies, and continuous improvement of team capability Engage with a technical and non-technical audience, acting as a trusted security advisor 🧠 What You Bring Core Skills: 4+ years of penetration testing experience (infrastructure/internal focus) Strong hands-on expertise with Active Directory attacks, lateral movement, and privilege escalation Experience navigating live and legacy production systems Comfortable in Windows More ❯

Senior Penetration Tester -240,000+ Total Package Entasis Partners are proud to be exclusively supporting a global organisation at the forefront of innovation in financial systems and high-performance computing. This is not your average security role. Our partner operates in a deeply technical, high-trust environment where the scale of data, the pace of experimentation, and the … of internal talent make for an exceptionally challenging and rewarding opportunity. With a newly developed central London site focused on next-generation research, this firm is seeking a Senior Penetration Tester to strengthen its already world-class internal security capability. The Opportunity This is a hands-on, highly autonomous role embedded within a specialist cyber function. You’ll … be trusted to scope, execute, and deliver sophisticated penetration tests and control assessments across a range of technologies including Kubernetes, Jenkins, and Windows-based infrastructure. More than just finding issues, you’ll work in partnership with teams across the business to advise, remediate, and embed meaningful improvements. The environment is agile, collaborative, and engineered for depth not red tape. More ❯

Senior Penetration Tester -240,000+ Total Package Entasis Partners are proud to be exclusively supporting a global organisation at the forefront of innovation in financial systems and high-performance computing. This is not your average security role. Our partner operates in a deeply technical, high-trust environment where the scale of data, the pace of experimentation, and the … of internal talent make for an exceptionally challenging and rewarding opportunity. With a newly developed central London site focused on next-generation research, this firm is seeking a Senior Penetration Tester to strengthen its already world-class internal security capability. The Opportunity This is a hands-on, highly autonomous role embedded within a specialist cyber function. You’ll … be trusted to scope, execute, and deliver sophisticated penetration tests and control assessments across a range of technologies including Kubernetes, Jenkins, and Windows-based infrastructure. More than just finding issues, you’ll work in partnership with teams across the business to advise, remediate, and embed meaningful improvements. The environment is agile, collaborative, and engineered for depth not red tape. More ❯

Senior Penetration Tester -240,000+ Total Package Entasis Partners are proud to be exclusively supporting a global organisation at the forefront of innovation in financial systems and high-performance computing. This is not your average security role. Our partner operates in a deeply technical, high-trust environment where the scale of data, the pace of experimentation, and the … of internal talent make for an exceptionally challenging and rewarding opportunity. With a newly developed central London site focused on next-generation research, this firm is seeking a Senior Penetration Tester to strengthen its already world-class internal security capability. The Opportunity This is a hands-on, highly autonomous role embedded within a specialist cyber function. You’ll … be trusted to scope, execute, and deliver sophisticated penetration tests and control assessments across a range of technologies including Kubernetes, Jenkins, and Windows-based infrastructure. More than just finding issues, you’ll work in partnership with teams across the business to advise, remediate, and embed meaningful improvements. The environment is agile, collaborative, and engineered for depth not red tape. More ❯

Harrington Starr have partnered with a global multi billion pound business in Belfast as they seek a Vulnerability and Penetration Testing Engineer to join their Belfast Centre team in providing security architecture, vulnerability and risk assessment. We are open to speaking to suitable canddiates who may be open to working ona remote contract with occasional trips to the Belfast … for WhiteHat/Ethical Hacking. Experience with automated tools such as Nessus, Appscan, Burp Suite, Nipper, and Trustwave. Expert understanding of the difference between a vulnerability assessment and a penetration test in the context of assessment scope, objectives, and deliverables. Working knowledge of information security frameworks such as ISO27001, NIST, and CIS. If this sounds like a good opportunity More ❯

Senior Penetration Tester -240,000+ Total Package Entasis Partners are proud to be exclusively supporting a global organisation at the forefront of innovation in financial systems and high-performance computing. Our partner operates in a deeply technical, high-trust environment where the scale of data, the pace of experimentation, and the calibre of internal talent make for an … exceptionally challenging and rewarding opportunity. With a newly developed central London site focused on next-generation research, this firm is seeking a Senior Penetration Tester to strengthen its already world-class internal security capability. You ll be trusted to scope, execute, and deliver sophisticated penetration tests and control assessments across a range of technologies including Kubernetes, Jenkins … and Windows-based infrastructure. The environment is agile, collaborative, and engineered for depth not red tape. Leading advanced penetration tests across infrastructure, applications, and DevOps pipelines Assessing the effectiveness of existing security controls through hands-on testing Working closely with Detection, Risk and Compliance teams to provide assurance and technical insight Coaching and supporting junior colleagues through knowledge sharing More ❯

Role: Penetration Tester Location: London Salary: £45k - £60k Work Pattern: On-Site For 3 Months and Then 3 Days On-Site/2 Days WFH Skillset: OWASP, Cloud Platforms, SSL/TLS Summary An elite security consultancy has a brand new role for an experienced Penetration Tester to join their team. The role is being offered … Cloud Platforms OSI Model Benefits Annual Training and Development Plans Regular Performance Reviews Industry Events and Conferences Hybrid Working After Probation Period Apply Now! If you are an experienced Penetration Tester and you are looking to progress with an organisation alongside ambitious and driven professionals, then look no further - this is the role for you! Referrals: If this … Email: to recommend someone for this role. Interviews for this role will be held imminently. To be considered, please send your CV to me now to avoid disappointment. Role: Penetration Tester Location: London Salary: £45k - £60k Work Pattern: On-Site For 3 Months and Then 3 Days On-Site/2 Days WFH Skillset: OWASP, Cloud Platforms, SSL More ❯