GHSA-pcw7-5633-82vv
GHSA-pcw7-5633-82vv is a Unrestricted File Upload vulnerability in @strapi/upload. O3 Security confirms whether GHSA-pcw7-5633-82vv is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Strapi Upload Plugin MIME Validation Bypass via Content API
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@strapi/uploadnpmDescription
Summary of CVE-2026-22707 Vulnerability Details
- CVE: CVE-2026-22707
- CVSS v3.1 Vector:
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N(5.3 — Medium) - Affected Versions:
@strapi/upload<=5.33.2 - How to Patch: Immediately update your Strapi to >=5.33.3
Description of CVE-2026-22707
In Strapi versions prior to 5.33.3, the Upload plugin's Content API endpoints did not enforce the administrator-configured MIME type restrictions (plugin.upload.security.allowedTypes and deniedTypes). The same restrictions were correctly enforced on the Admin Panel upload path.
The upload plugin's enforceUploadSecurity security check was invoked in the admin upload controller but was missing from the Content API controller. The Content API handlers uploadFiles and replaceFile (and the upload wrapper that dispatches to them) called the underlying upload service directly, bypassing both the magic-byte MIME detection and the configured allow/deny lists.
An authenticated user with the Content API upload permission could therefore upload file types the administrator had explicitly disallowed, including HTML and SVG content. In deployments serving uploaded files from the same origin as the admin panel (default), an attacker could upload an HTML or SVG file that, when opened directly by an admin, executed JavaScript in the admin origin, enabling admin-session hijack and authenticated administrative actions against the admin API.
The patch introduces a shared prepareUploadRequest helper that wraps enforceUploadSecurity and is called from both the Content API and admin upload controllers, ensuring identical security policy enforcement on every upload entry point.
IoC's for CVE-2026-22707
Indicators that an instance running an unpatched version may have been exploited:
- Files in
/uploads/with extensions outside the configured allow-list, particularly.html,.htm,.svg,.js,.mjs,.xml, or.xhtml. Filesystem regex:\.(html?|svg|m?js|x?html|xml)$ - Successful 201 responses from
POST /api/uploadwhere the uploaded file's MIME or extension is outside the configuredallowedTypes - Server access logs showing non-administrator users uploading files with executable web content types. Content-Type regex:
text/html|application/javascript|image/svg\+xml - Admin browsing logs (X-Forwarded-For, User-Agent) opening files under
/uploads/*.htmlor/uploads/*.svgshortly before unexpected administrative actions (user creation, role changes, permission modifications)
References
- CWE-693: Protection Mechanism Failure
- CWE-434: Unrestricted Upload of File with Dangerous Type
- OWASP: Unrestricted File Upload
- Strapi 5 Documentation - Media Library
- Strapi Security Policy
Credits
Reported independently by:
- @kaminuma (initial report, 2026-01-09)
- @arkmarta (concurrent report, 2026-01-13 — originally filed as GHSA-r7hp-523c-r8wr, closed as duplicate)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @strapi/upload | all versions | 5.33.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @strapi/upload. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @strapi/upload to 5.33.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pcw7-5633-82vv is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-pcw7-5633-82vv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pcw7-5633-82vv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pcw7-5633-82vv in your dependencies?
O3 detects GHSA-pcw7-5633-82vv across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.