Headless CMS Security Review
A headless CMS moves your content behind an API and your risk along with it. The recurring finding is not a broken platform. It is a delivery token with more scope than the front end needs, sitting in a JavaScript bundle anyone can read. CREST-certified testers, fixed price from £2,540, scoped in 24 hours.
- Unlimited retesting
- No rescheduling or cancellation fees
- Fixed quote within 24 hours
“I would highly recommend EJN Labs to any organisation seeking reliable, detailed, and well-managed penetration testing services, particularly for government or enterprise-level projects.”
Imran SaghirProject Lead, SquareOne“There wasn’t another company we could find that could deliver what we needed in the timeframe we needed. The client loved it, and we got instant ROI from the engagement.”
Dan WilcocksonCo-Founder, CelloriPlatforms such as Contentful, Sanity and Strapi, among others, are well built and well maintained. What goes wrong is almost always the integration: which token the front end carries, what that token can reach, and whether anything not yet published is reachable with it.
Why headless shifts the risk to the token
Preview and draft content is the second pattern. A preview token issued for an editor’s convenience finds its way into a build, and unpublished content, embargoed announcements and internal notes become readable by anyone who opens developer tools.
The third is webhooks. Content updates trigger rebuilds and downstream jobs, and those endpoints frequently accept anything that reaches them. We pen test all three, plus the roles behind the authoring interface.
ISO 27001, SOC 2, PCI DSS and Cyber Essentials Plus audits accept manual penetration test evidence. Scan-only evidence is generally insufficient.
TOKENS, DRAFTS + WEBHOOKS
What we actually pen test on a headless CMS
Manual pen testing across token scope, draft and preview exposure, the delivery API, webhook verification and the roles behind the authoring interface.
API token scope and exposure
Every token in use enumerated and tested for what it can actually reach, including whether a delivery token can read drafts, whether a management token has leaked into a client bundle, and whether tokens can be rotated at all.
Draft and preview content leakage
Whether unpublished, scheduled or embargoed content is retrievable through the delivery API, the preview API, the GraphQL schema or a stale cache.
Roles and authoring permissions
Editor, contributor and administrator boundaries in the authoring interface, including whether a contributor can publish, change content models or issue tokens.
Webhook and build pipeline verification
Whether webhook receivers verify signatures and origin, whether a forged request can trigger a rebuild or a deployment, and what the build environment exposes in its logs.
Delivery API and query abuse
GraphQL introspection and query depth where the platform exposes it, filter and field selection abuse to reach content outside the intended set, and rate limiting on the delivery endpoints.
Self-hosted deployment
For self-hosted platforms such as Strapi, the admin panel exposure, default credentials, plugin surface, upload handling and the database and file storage behind it.
METHODOLOGY
Headless CMS Security Review: From Scope to Attestation
CREST-aligned methodology built on OWASP Web Security Testing Guide, OWASP ASVS, NIST SP 800-115, and PTES. Each finding maps to all four standards plus your specific compliance regime.
Reconnaissance
Application mapping, technology fingerprinting, content discovery, parameter enumeration, authentication-flow analysis, role-matrix construction.
Vulnerability Assessment
Authenticated and unauthenticated automated scanning across every user role, plus targeted manual checks for known weakness patterns.
Manual Exploitation
Hands-on testing by a CREST-certified pentester. Business-logic exploitation, chained vulnerabilities, privilege escalation, impact validation.
Reporting + Retest
Executive summary, technical report with CVSS scores and reproduction steps, walkthrough call, free retest after remediation, attestation letter.
CREDENTIALS
Verified Accreditations Auditors Accept
Every credential below is independently verifiable. UK procurement teams, FCA supervisors, ISO 27001 / SOC 2 auditors, and cyber insurance underwriters all recognise these standards.
GET YOUR QUOTE
Get a CREST headless CMS pen test quote in 24 hours
A fixed-price quote back in one business day, from a named CREST assessor. No sales pipeline, no chasing.
- CREST and IASME accredited. Testing your auditors and clients already recognise.
- Fast-track testing within 24 hours where required. Free retest of every fix included.
- Live findings via your client portal, not a four-week PDF.
- Fixed price from £3,500 for a single-role, single-app scope, agreed up front. Most engagements run £5,000 and up. No day-rate surprises.
Dan WilcocksonCo-Founder, CelloriUnder NDA Further named references available on a scoping call.
- We reply within one business day with a fixed-price quote from a named CREST assessor.
- You approve the scope and we book a start date, usually within 24 hours.
- Live findings land in your client portal as we test, with a free retest of every fix.
Get your fixed pen test quote in 24 hours
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COMPLIANCE READY
Reports Mapped to Every Framework
Findings are explicitly tagged to the relevant control reference. Your audit team submits the report directly without translation work.
ISO 27001:2022
Annex A.8.8 management of technical vulnerabilities plus A.5.15-5.18 and A.8.2-8.5 access control validation.
SOC 2 Type I & II
CC6 logical access, CC7 system operations, CC8 change management evidence.
PCI DSS
Requirement 11.4 application penetration testing across cardholder data environments, including ecommerce penetration testing for online retail platforms.
FCA SYSC
SYSC 4.1.1R, 6.1.1R, 13 mapped to each finding for FCA-regulated firms.
UK GDPR
Article 32 effectiveness testing, customer-data security controls, ICO-acceptable evidence.
Cyber Essentials Plus
Direct certification through our IASME body status, single-vendor delivery.
PRICING
Transparent Headless CMS Security Review Pricing
Pricing depends on app complexity, user-role count, business-logic depth, and integration surface. The day count flexes; the included deliverables stay the same across all engagements.
2 to 3 testing days
Single user role, basic CRUD application, marketing website with auth. Around 5 working days from kickoff to report.
Get a fixed quote3 to 5 testing days
Multi-role SaaS, business application with payment integration. Around 8 to 12 working days from kickoff to report.
Get a fixed quote5 to 7 testing days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. Around 15 to 20 working days from kickoff to report.
Get a fixed quotePart of Technologies We Pen Test. These are examples of the stacks we publish pages for, not a complete list. If yours is not here we still test it. Related pages:
BY SECTOR
Headless CMS Security Review for Your Sector
Sector-specialist scoping for UK businesses with sector-specific compliance regimes and threat models.
Fintech & FCA-Regulated
FCA SYSC, Open Banking FAPI 1.0, PSD2 SCA, payment-flow scrutiny, KYC/AML testing.
Fintech sector pageSaaS Companies
SOC 2 Type I & II evidence, multi-tenant boundaries, role escalation, customer-tenant isolation.
SaaS sector pageLaw Firms
SRA Cyber Standard, privileged data, conveyancing fraud defence, partner-tier procurement.
Law firm sector pageHealthcare
NHS DTAC, DSP Toolkit v6, UK GDPR Article 32, EHR systems, telehealth platforms.
Healthcare sector pageInsurance
FCA / PRA Operational Resilience, cyber underwriting, claims data, broker portals.
Insurance sector pagePublic Sector
CCS / G-Cloud framework, NCSC-aligned, citizen-facing services, PSN-compliance scrutiny.
Public sector pageWHY EJN LABS
What You Get From Headless CMS Security Review
Six concrete differentiators competitors don’t all match.
CREST-Certified Testers, Verifiable
Every test by a CREST-certified pen tester (CRT, CCT APP, CCT INF where applicable). Verify our company status at crest-approved.org.
24-Hour Startup, Where Required
From signed scope to active testing in a single business day for incident response, audit deadlines, or regulator-driven timelines.
Live Findings, Not 4-Week PDFs
Critical issues reported during testing through your client portal. Your team remediates while testing continues.
Audit-Ready Reports
Executive summary plus full technical report with CVSS scores and explicit framework mappings (ISO 27001, SOC 2, PCI DSS, FCA SYSC).
Free Retests, Standard
Verify remediation of every finding before close-out. Letter of attestation for audit submission included. Most competitors charge £1,500-£3,000 per retest.
UK-Based CREST Testers
Every engagement performed by vetted, UK-based CREST-certified testers, matched to your needs, security clearance, and compliance scope.
FAQ
Frequently Asked
Which platforms does this cover?
Contentful, Sanity and Strapi are the ones we see most, and this page is scoped around them. They are examples rather than a complete list: if you run a different headless platform we still pen test it, and the approach does not change.
The platform is SaaS. What is actually in scope?
Your configuration and your integration, which is where the findings are. We do not attack the vendor’s infrastructure and would not be permitted to. We pen test what you control: tokens, roles, content models, the delivery API and everything downstream of it.
What about the front end that consumes it?
Often worth including, because the token and the rendering live there. If your front end is Next.js, Vue or React we can scope both together and price it as one engagement rather than two.
Do you need admin access?
One account per role is ideal, plus the token list. We can work with less, but a black box test of a headless CMS mostly finds what is already public, which is not the point.
Is Strapi treated differently?
Yes, because you host it. That brings the admin panel, the upload handling, the plugin surface and the underlying database into scope, so a self-hosted Strapi review runs longer than a review of a hosted platform.
20+ CREST-accredited testing services in one place
Web, mobile, API, cloud, AI, infrastructure, red team. Pick the test that fits your environment.
Get a fixed price for your headless stack
Tell us the platform, the token list and whether the front end is in scope. You get a fixed-price quote from a named CREST assessor within one business day, unlimited retesting and no cancellation fees.
