Paper/Archive/CVE-2026-30884

CVE-2026-30884

mdjnelson moodle-mod_customcert — mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key

EPSS 0.2%public exploit CVSS 9.6

critical.is priorityof 100

CVSS 9.6 (CNA)9.6 / 10 × 3028.8 Not in CISA KEV+300.0 EPSS percentile 6.9.069 × 201.4 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

moodle-mod_customcert< 4.4.9–CNA

moodle-mod_customcert>= 5.0.0, < 5.0.3–CNA

Scores by source

GitHub_M (CNA)9.6CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

refgithub.com/mdjnelson/moodle-mod_customcert/security/advisories/GHSA-8pjr-j7r4-ccjx refgithub.com/mdjnelson/moodle-mod_customcert/commit/a1494a80fb953f187f7888a7394cbf9d13c28468 refgithub.com/mdjnelson/moodle-mod_customcert/commit/ddc8f01f1e19fb61202f6013a38ef757486d3ba0