CVE-2026-102583: Moodle AI Editor Auth Bypass Vulnerability

CVE-2026-102583 Overview

A missing authorization flaw exists in Moodle's artificial intelligence (AI) editor placement. The image generation web service fails to enforce the required capability check before invoking the underlying functionality. An authenticated user without the appropriate capability can call the endpoint and use the AI image generation feature. The issue is tracked as [CWE-425: Direct Request ('Forced Browsing')] and corresponds to Moodle issue MDL-88587.

Critical Impact
Authenticated Moodle users can invoke the AI image generation web service without holding the required capability, resulting in unauthorized use of AI resources.

Affected Products

Moodle Learning Management System — AI editor placement component
Image generation web service exposed by the AI subsystem
Deployments packaged and tracked by Red Hat (see Red Hat CVE-2026-102583)

Discovery Timeline

2026-09-30 - CVE CVE-2026-102583 published to NVD
2026-09-30 - Last updated in NVD database

Technical Details for CVE-2026-102583

Vulnerability Analysis

The vulnerability resides in the AI editor placement image generation web service. Moodle exposes AI features to end users through capability-gated web services. A capability is Moodle's role-based permission primitive that authorizes a user to perform a specific action.

The image generation entry point does not verify the required capability before executing the request. Any authenticated user, including low-privilege roles, can invoke the service and generate images through the configured AI provider. The impact is limited to unauthorized use of the AI feature and associated resource consumption.

The flaw is categorized under [CWE-425] because the server relies on the client to only request functionality it is entitled to, rather than enforcing that entitlement server-side. See the Moodle Forum Discussion #482501 and Red Hat Bugzilla Report 2543640 for additional context.

Root Cause

The web service handler for AI image generation omits a require_capability() (or equivalent) check against the caller's role. Authorization was assumed at the user interface layer rather than enforced at the service boundary. The fix in Moodle Commit MDL-88587 adds the missing server-side capability enforcement.

Attack Vector

Exploitation requires authenticated access to a Moodle instance with the AI editor placement enabled and an image generation provider configured. The attacker sends a direct request to the AI image generation web service endpoint. Because the capability check is missing, the request executes even though the caller lacks the intended permission. No user interaction beyond the authenticated session is required.

No public proof-of-concept, exploit code, or CISA KEV listing is associated with this issue at the time of publication.

Detection Methods for CVE-2026-102583

Indicators of Compromise

Web service calls to the AI editor placement image generation endpoint originating from user accounts whose roles do not include the AI image generation capability.
Unexpected spikes in outbound API calls or billing from the configured AI image provider.
Moodle web service logs showing image generation requests from student or guest-level roles.

Detection Strategies

Correlate Moodle access logs with role-to-capability mappings to identify requests to /webservice/ AI endpoints from users lacking the required capability.
Monitor the Moodle mdl_logstore_standard_log table for AI placement actions performed by unexpected role IDs.
Alert on any invocation of the AI image generation service prior to applying the MDL-88587 fix.

Monitoring Recommendations

Enable verbose logging on Moodle web services and forward logs to a centralized SIEM for role-based analysis.
Track AI provider API consumption metrics and set thresholds that alert on anomalous per-user usage.
Review Moodle role and capability audit reports on a recurring basis to confirm least-privilege assignment.

How to Mitigate CVE-2026-102583

Immediate Actions Required

Apply the Moodle security update that includes the MDL-88587 commit as soon as it is available for your release branch.
If patching is delayed, disable the AI editor placement or the image generation provider in Site administration until the fix is deployed.
Audit the users and roles that hold AI-related capabilities and remove unnecessary grants.

Patch Information

The upstream fix is tracked in Moodle issue MDL-88587 and adds the missing capability enforcement in the AI editor placement image generation web service. Distribution-specific advisories are published by Red Hat at Red Hat CVE-2026-102583. Administrators running Moodle from Linux distribution packages should apply vendor-supplied updates once released.

Workarounds

Disable the AI subsystem or the image generation placement in Moodle Site administration until the patch is applied.
Remove or disable the configured AI image generation provider credentials to prevent downstream API calls.
Restrict access to the Moodle web service endpoint at the network layer (for example, via a reverse proxy allowlist) while remediation is in progress.

bash

# Configuration example: disable the AI image generation placement via CLI
php admin/cli/cfg.php --component=aiplacement_editor --name=image_enabled --set=0

# Verify the setting
php admin/cli/cfg.php --component=aiplacement_editor --name=image_enabled