GHSA-fxp3-g6gw-4r4v
Craft CMS: GraphQL Asset Mutation Privilege Escalation
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
There is a Privilege Escalation vulnerability in Craft CMS’s GraphQL API that allows an authenticated user with write access to one asset volume to escalate their privileges and modify/transfer assets belonging to any other volume, including restricted or private volumes to which they should not have access.
Summary:
Type: Privilege Escalation (CWE-269)
Affected: Craft CMS 5.x (likely affects 4.x and 3.x as well)
Location: src/gql/resolvers/mutations/Asset.php lines 57-107
Root Cause:
The saveAsset GraphQL mutation validates authorization against the schema-resolved volume but fetches the target asset by ID without verifying that the asset belongs to the authorized volume. This allows unauthorized cross-volume asset modification and transfer.
Impact:
- Transfer confidential assets from private volumes to public volumes (data exfiltration)
- Modify asset metadata in restricted volumes
- Bypass multi-tenant isolation in shared hosting environments
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.9.0-beta.1 | 5.9.0-beta.1 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.17.0-beta.1 | 4.17.0-beta.1 |
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 5.9.0-beta.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fxp3-g6gw-4r4v 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-fxp3-g6gw-4r4v 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-fxp3-g6gw-4r4v. 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-fxp3-g6gw-4r4v in your dependencies?
O3 detects GHSA-fxp3-g6gw-4r4v across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.