Critical 9.6Published Mar 17, 2026

CVE-2026-30884mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key

Updated under an hour ago (Oct 28, 2026, 4:50 AM ET)

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Every CVE for mdjnelson moodle-mod_customcert

Exploited in the last 30 days

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 single course can read and silently overwrite certificate elements belonging to any other course in the Moodle installation. The `core_get_fragment` callback `editelement` and the `mod_customcert_save_element` web service both fail to verify that the supplied `elementid` belongs to the authorized context, enabling cross-course information disclosure and data tampering. Versions 4.4.9 and 5.0.3 fix the issue.

CVSS: 9.6 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Weakness (CWE): CWE-639
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Mar 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mdjnelson moodle-mod_customcert mdjnelson:moodle_mod_customcert (from the name)	before 4.4.9; from 5.0.0, < 5.0.3	CNA record

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.