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Critical · 9.6 CVE-2026-30884 EUVD-2026-12745

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

Published Mar 18, 2026 · Updated Mar 18, 2026 · Assigned by GitHub_M

Description

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 products

VendorProductAffectedFixed
mdjnelson moodle-mod_customcert < 4.4.9, >= 5.0.0, < 5.0.3 —

References