What is CVE-2026-30884?

CVE-2026-30884 is a critical-severity vulnerability in Mdjnelson Moodle-mod_customcert, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.6/10. Published 2026-03-18.

How severe is CVE-2026-30884?

Critical severity. CVSS v3 base score is 9.6 out of 10.

Auth bypass in Mdjnelson Moodle-mod_customcert

CVE-2026-30884

mdjnelson/moodle-mod_customcert is a Moodle plugin for creating dynamically generated certificates with complete customization via the web browser. Prior to versions 4.4.9 and 5.0.3, a teacher who holds `mod/customcert:manage` in any singl…

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.000 (6.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.

Affected products

Mdjnelson Moodle-mod_customcert — versions < 4.4.9, >= 5.0.0, < 5.0.3

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

https://github.com/mdjnelson/moodle-mod_customcert/security/advisories/GHSA-8pjr-j7r4-ccjx (x_refsource_CONFIRM)
https://github.com/mdjnelson/moodle-mod_customcert/commit/a1494a80fb953f187f7888a7394cbf9d13c28468 (x_refsource_MISC)
https://github.com/mdjnelson/moodle-mod_customcert/commit/ddc8f01f1e19fb61202f6013a38ef757486d3ba0 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-30884?: CVE-2026-30884 is a critical-severity vulnerability in Mdjnelson Moodle-mod_customcert, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.6/10. Published 2026-03-18.
How severe is CVE-2026-30884?: Critical severity. CVSS v3 base score is 9.6 out of 10.