CVE-2023-28336 is a medium-severity (CVSS 4.3) Information Exposure vulnerability in moodle/moodle. A fix is available for moodle/moodle — see the affected versions and patch details below.
Moodle: teacher can access names of users they do not have permission to access
Exploitation Status
No confirmed exploitation observed yet
- 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-2023-28336.
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
Insufficient filtering of grade report history made it possible for teachers to access the names of users they could not otherwise access.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | moodle/moodle | ≥ 4.1.0&&< 4.1.2 | 4.1.2composer require moodle/moodle:^4.1.2 |
| 🐘Packagist | moodle/moodle | ≥ 4.0.0&&< 4.0.7 | 4.0.7composer require moodle/moodle:^4.0.7 |
| 🐘Packagist | moodle/moodle | ≥ 3.11.0&&< 3.11.13 | 3.11.13composer require moodle/moodle:^3.11.13 |
| 🐘Packagist | moodle/moodle | all versions | 3.9.20composer require moodle/moodle:^3.9.20 |
Affected Products
fedorafedoraprojectmoodlemoodleDetection & 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 4.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28336 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2023-28336 in your dependencies?
Find it across Packagist, including transitive dependencies.