CVE-2025-26529 — moodle
HIGHCVE-2025-26529 is a high-severity (CVSS 8.3) Cross-site Scripting (XSS) vulnerability in moodle/moodle. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for moodle/moodle — see the affected versions and patch details below.
Stored XSS risk in admin live log
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 CVE-2025-26529.
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/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
Description information displayed in the site administration live log required additional sanitizing to prevent a stored XSS risk.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | moodle/moodle | ≥ 4.5.0-beta&&< 4.5.2 | 4.5.2composer require moodle/moodle:^4.5.2 |
| 🐘Packagist | moodle/moodle | ≥ 4.4.0-beta&&< 4.4.6 | 4.4.6composer require moodle/moodle:^4.4.6 |
| 🐘Packagist | moodle/moodle | ≥ 4.3.0-beta&&< 4.3.10 | 4.3.10composer require moodle/moodle:^4.3.10 |
| 🐘Packagist | moodle/moodle | all versions | 4.1.16composer require moodle/moodle:^4.1.16 |
Affected Products
moodlemoodleResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & 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 4.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-26529 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 CVE-2025-26529 in your dependencies?
Find it across Packagist, including transitive dependencies.