GHSA-5pgf-h923-m958 — craftcms/cms
Fix: craftcms/cms@7290d91GHSA-5pgf-h923-m958 is a CWE-639 vulnerability in craftcms/cms. A fix is available for craftcms/cms — see the affected versions and patch details below.
Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-5pgf-h923-m958.
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
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 | 5.9.14composer require craftcms/cms:^5.9.14 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.17.8 | 4.17.8composer require craftcms/cms:^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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-5pgf-h923-m958 can be triaged on real exposure rather than presence alone.
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 Security finds GHSA-5pgf-h923-m958 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.