GHSA-2xfc-g69j-x2mp
Craft CMS: Entries Authorship Spoofing via Mass Assignment
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
Description
The entry creation process allows for Mass Assignment of the authorId attribute. A user with "Create Entries" permission can inject the authorIds[] (or authorId) parameter into the POST request, which the backend processes without verifying if the current user is authorized to assign authorship to others.
Normally, this field is not present in the request for users without the necessary permissions. By manually adding this parameter, an attacker can attribute the new entry to any user, including Admins. This effectively "spoofs" the authorship.
Proof of Concept
Prerequisites
- A user account with "Create Entries" permission for a section.
- Victim's account ID (e.g.,
1for the default Admin).
Steps to Reproduce
- Log in as the attacker
- Navigate to the "Entries" section and click "New Entry"
- Fill in the required fields
- Enable a proxy tool (e.g., Burp Suite) to intercept requests
- Click "Save" & Intercept the request
- In the request body, add a new parameter to the body params:
&authorIds[]=<Victim_ID> - Forward the request
- Log in as an admin / as with the victim account
- Go to entries & Observe the newly created entry is listed and the author is the victim account, not the actual creator
Impact
- A user can create entries that appear to belong to higher-privileged users, potentially bypassing review processes or gaining trust based on false authorship.
- An attacker could post malicious or inappropriate content attributed to an administrator or other trusted users.
Resources
https://github.com/craftcms/cms/commit/c6dcbdffaf6ab3ffe77d317336684d83699f4542 https://github.com/craftcms/cms/commit/830b403870cd784b47ae42a3f5a16e7ac2d7f5a8
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-2xfc-g69j-x2mp 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-2xfc-g69j-x2mp 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-2xfc-g69j-x2mp. 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-2xfc-g69j-x2mp in your dependencies?
O3 detects GHSA-2xfc-g69j-x2mp across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.