GHSA-r3fc-hx6q-g6cq 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 allows attackers to discover student e-mail addresses
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.
How urgent is this, really
GHSA-r3fc-hx6q-g6cq plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
user/index.php in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 grants excessive authorization on the basis of the moodle/course:viewhiddenuserfields capability, which allows remote authenticated users to discover student e-mail addresses by leveraging the teacher role and reading a Participants list.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | moodle/moodle | all versions | 2.7.13composer require moodle/moodle:^2.7.13 |
| 🐘Packagist | moodle/moodle | ≥ 2.8.0&&< 2.8.11 | 2.8.11composer require moodle/moodle:^2.8.11 |
| 🐘Packagist | moodle/moodle | ≥ 2.9.0&&< 2.9.5 | 2.9.5composer require moodle/moodle:^2.9.5 |
| 🐘Packagist | moodle/moodle | ≥ 3.0.0&&< 3.0.3 | 3.0.3composer require moodle/moodle:^3.0.3 |
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 2.7.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r3fc-hx6q-g6cq 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-r3fc-hx6q-g6cq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-r3fc-hx6q-g6cq. 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-r3fc-hx6q-g6cq in your dependencies?
O3 Security finds GHSA-r3fc-hx6q-g6cq across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.