9.6
CRITICAL CVSS 3.1
CVE-2026-30884
mdjnelson/moodle-mod_customcert Vulnerable to Authorization Bypass Through User-Controlled Key
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.

INFO

Published Date :

March 18, 2026, 4:17 a.m.

Last Modified :

March 18, 2026, 4:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-30884 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update the Moodle custom certificate plugin to versions 4.4.9 or 5.0.3 to fix authorization flaws.
  • Update the Moodle custom certificate plugin to version 4.4.9.
  • Update the Moodle custom certificate plugin to version 5.0.3.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-30884 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-30884 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-30884 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-30884 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 18, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
    Added CWE CWE-639
    Added Reference https://github.com/mdjnelson/moodle-mod_customcert/commit/a1494a80fb953f187f7888a7394cbf9d13c28468
    Added Reference https://github.com/mdjnelson/moodle-mod_customcert/commit/ddc8f01f1e19fb61202f6013a38ef757486d3ba0
    Added Reference https://github.com/mdjnelson/moodle-mod_customcert/security/advisories/GHSA-8pjr-j7r4-ccjx
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.