How severe is GHSA-fp5j-j7j4-mcxc?

No CVSS score has been assigned to GHSA-fp5j-j7j4-mcxc yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-fp5j-j7j4-mcxc?

GHSA-fp5j-j7j4-mcxc affects the following packages: craftcms/cms (Packagist), craftcms/cms (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-fp5j-j7j4-mcxc?

Update craftcms/cms to 5.9.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fp5j-j7j4-mcxc is resolved across your whole dependency graph.

How do I detect GHSA-fp5j-j7j4-mcxc in my Packagist dependencies?

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.

How do I mitigate GHSA-fp5j-j7j4-mcxc if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-fp5j-j7j4-mcxc?

O3 pinpoints whether GHSA-fp5j-j7j4-mcxc is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-fp5j-j7j4-mcxc actively exploited in the wild?

No public exploit code has been indexed for GHSA-fp5j-j7j4-mcxc yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-fp5j-j7j4-mcxc?

GHSA-fp5j-j7j4-mcxc has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 47th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-fp5j-j7j4-mcxc published, and has it been updated?

GHSA-fp5j-j7j4-mcxc was published on March 11, 2026 and was last updated on March 13, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

GHSA-fp5j-j7j4-mcxc

CraftCMS has an RCE vulnerability via relational conditionals in the control panel

Also known asCVE-2026-31857

Published

Mar 11, 2026

Updated

Mar 13, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk47th percentile+0.53%

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

2 pkgs affected

🐘craftcms/cms🐘craftcms/cms

Real-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

A Remote Code Execution vulnerability exists in the Craft CMS 5 conditions system.

The BaseElementSelectConditionRule::getElementIds() method passes user-controlled string input through renderObjectTemplate() -- an unsandboxed Twig rendering function with escaping disabled.

Any authenticated Control Panel user (including non-admin roles such as Author or Editor) can achieve full RCE by sending a crafted condition rule via standard element listing endpoints.

This vulnerability requires no admin privileges, no special permissions beyond basic control panel access, and bypasses all production hardening settings (allowAdminChanges: false, devMode: false, enableTwigSandbox: true).

Users should update to the patched 5.99 release to mitigate the issue.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`craftcms/cms`	≥ 5.0.0-RC1&&< 5.9.9	5.9.9
🐘Packagist	`craftcms/cms`	≥ 4.0.0-beta.1&&< 4.17.4	4.17.4

Detection & mitigation playbook

Open-source dependency

Detect
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 5.9.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fp5j-j7j4-mcxc 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-fp5j-j7j4-mcxc 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-fp5j-j7j4-mcxc. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A Remote Code Execution vulnerability exists in the Craft CMS 5 conditions system. The `BaseElementSelectConditionRule::getElementIds()` method passes user-controlled string input through `renderObjectTemplate()` -- an unsandboxed Twig rendering function with escaping disabled. Any authenticated Control Panel user (including non-admin roles such as Author or Editor) can achieve full RCE by sending a crafted condition rule via standard element listing endpoints. This vulnerability requires no admin privileges, no special permissions beyond basic control panel access, and bypasses all product

O3 Security · Impact-Aware SCA

Is GHSA-fp5j-j7j4-mcxc in your dependencies?

O3 detects GHSA-fp5j-j7j4-mcxc across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works