GHSA-5pgf-h923-m958
Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL
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.
Blast Radius
craftcms/cms🐘craftcms/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
An unauthenticated user can call assets/generate-transform with a private assetId, receive a valid transform URL, and fetch transformed image bytes.
The endpoint is anonymous and does not enforce per-asset authorization before returning the transform URL.
Details
Root cause:
- Anonymous endpoint accepts user-controlled asset reference.
- It creates and returns a transform URL for that asset without checking access rights.
- If the transform output is reachable, guest users can read content derived from private assets.
Who is impacted:
- Installations where private source assets can be transformed and transform URLs are reachable.
Security consequence:
- Anonymous users can obtain content derived from private assets without authentication.
Resources
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.9.14 | 5.9.14 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.17.8 | 4.17.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. 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 craftcms/cms to 5.9.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5pgf-h923-m958 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-5pgf-h923-m958 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-5pgf-h923-m958. 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-5pgf-h923-m958 in your dependencies?
O3 detects GHSA-5pgf-h923-m958 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.