CVE-2026-30884
mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.6
mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key
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.
- Record
CVE-2026-30884- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2026-12745
9.6
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.
- Record
EUVD-2026-12745- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
NVD
9.6
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.
- Record
CVE-2026-30884- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
OSV
9.6
mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key
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.
- Record
CVE-2026-30884- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-30884 is a critical vulnerability (CVSS 9.6) in Mdjnelson Moodle-mod Customcert, published March 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.
References
github.com/mdjnelson/moodle-mod_customcert/security/advisories/GHSA-8pjr-j7r4-ccjx
github.com/mdjnelson/moodle-mod_customcert/commit/a1494a80fb953f187f7888a7394cbf9d13c28468
github.com/mdjnelson/moodle-mod_customcert/commit/ddc8f01f1e19fb61202f6013a38ef757486d3ba0
github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30884.json
nvd.nist.gov/vuln/detail/CVE-2026-30884