GHSA-6mmv-f6c6-v6q8 is a high-severity (CVSS 7.3) Cross-site Scripting (XSS) vulnerability in moodle/moodle. A fix is available for moodle/moodle — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-6mmv-f6c6-v6q8.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
moodle/moodle🐘moodle/moodle🐘moodle/moodle🐘moodle/moodle🐘moodle/moodleReal-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 flaw was found in Moodle. This vulnerability, known as Cross-site Scripting (XSS), occurs due to insufficient checks on user-provided data in the formula editor's arithmetic expression fields. A remote attacker could inject malicious code into these fields. When other users view these expressions, the malicious code would execute in their web browsers, potentially compromising their data or leading to unauthorized actions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | moodle/moodle | all versions | 4.1.22composer require moodle/moodle:^4.1.22 |
| 🐘Packagist | moodle/moodle | ≥ 4.4.0-beta&&< 4.4.12 | 4.4.12composer require moodle/moodle:^4.4.12 |
| 🐘Packagist | moodle/moodle | ≥ 4.5.0-beta&&< 4.5.8 | 4.5.8composer require moodle/moodle:^4.5.8 |
| 🐘Packagist | moodle/moodle | ≥ 5.0.0-beta&&< 5.0.4 | 5.0.4composer require moodle/moodle:^5.0.4 |
| 🐘Packagist | moodle/moodle | ≥ 5.1.0-beta&&< 5.1.1 | 5.1.1composer require moodle/moodle:^5.1.1 |
Affected Products
moodlemoodleDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for moodle/moodle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update moodle/moodle to 4.1.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6mmv-f6c6-v6q8 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-6mmv-f6c6-v6q8 in your dependencies?
Find it across Packagist, including transitive dependencies.