CVE-2026-91133: Discourse

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, authenticated users could supply unescaped SQL LIKE metacharacters to upload-resolution patterns, causing wildcard input to select unrelated upload records instead of matching a literal identifier. The affected upload metadata, URL-lookup, and cooked-video-placeholder paths could resolve uploads the user was not authorized to access. This allowed disclosure of restricted metadata, including original filenames and secure-upload paths, without modifying the upload records. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

Affected products

• Discourse Discourse: before 2026.8.0 (fixed in 2026.8.0); from 2026.7.0-latest, before 2026.7.2 (fixed in 2026.7.2); from 2026.6.0-latest, before 2026.6.3 (fixed in 2026.6.3); from 2026.1.0-latest, before 2026.1.8 (fixed in 2026.1.8)

Published 2026-09-24. Last modified 2026-09-24.