Is this vulnerability remotely exploitable across the internet?

It is exploitable remotely through the Moodle web interface or web services, but only by authenticated users who already have the `mod/customcert:manage` capability in at least one course. Anonymous users cannot exploit this issue directly.

What level of access does an attacker need?

The attacker must be a legitimate user (typically a teacher or staff member) with permission to manage custom certificates in at least one course. From there, they can target certificate elements associated with other courses by manipulating the `elementid` parameter.

What is the safest general fix pattern for developers?

The robust fix pattern is to enforce object-level authorization: whenever a certificate element is loaded by ID, resolve its parent context (course, module instance) on the server and verify that the current user holds the appropriate capability in that exact context before allowing read or write operations.

Severity:

CRITICAL RISK

(9.6)

Insecure Direct Object Reference (CWE-639) in Moodle Custom Certificate Plugin Cross‑Course Element Access

CVE-2026-30884

Published:

Mar 17, 2026

Status:

Deferred

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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Privilege Escalation via Bypassed Access Control

May 6, 2026

Vulnerability Type

Category:

Insecure Direct Object Reference

CWE:

CWE-639

Impact:

Cross-Context Data Disclosure and Tampering

Severity:

CRITICAL RISK

(9.6)

CVSS Version:

3.1

Vulnerability Type

Category:

Insecure Direct Object Reference

CWE:

CWE-639

Impact:

Cross-Context Data Disclosure and Tampering

Severity:

CRITICAL RISK

(9.6)

CVSS Version:

3.1

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Insecure Direct Object Reference (CWE-639) in Moodle Custom Certificate Plugin Cross‑Course Element Access

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.6)

Server-Side Request Forgery (CWE-918) in OpenClaw Zalo Plugin sendPhoto

HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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