What is CVE-2023-5539?

CVE-2023-5539 is a medium-severity vulnerability in Moodle, classified under Code Injection. CVSS score: 4.7/10. Published 2023-11-09.

How severe is CVE-2023-5539?

Medium severity. CVSS v3 base score is 4.7 out of 10.

Is CVE-2023-5539 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Moodle

CVE-2023-5539

A remote code execution risk was identified in the Lesson activity. By default this was only available to teachers and managers.

Vulnerability class: RCE (Remote Code Execution)

Published 2023-11-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.019 (78.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Moodle
Fedoraproject Extra Packages For Enterprise Linux — versions 7.0
Fedoraproject Fedora — versions 38

Weakness classification (CWE)

CWE-94 — Code Injection

Public proof-of-concept exploits

References

git.moodle.org/gw (Patch)
bugzilla.redhat.com/show_bug.cgi (issue-tracking, Patch, Third Party Advisory, Issue Tracking)
moodle.org/mod/forum/discuss.php (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-5539?: CVE-2023-5539 is a medium-severity vulnerability in Moodle, classified under Code Injection. CVSS score: 4.7/10. Published 2023-11-09.
How severe is CVE-2023-5539?: Medium severity. CVSS v3 base score is 4.7 out of 10.
Is CVE-2023-5539 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.