CVE-2026-44783: Discourse

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, a flaw in how replies to whisper posts are handled allows authenticated users outside the groups configured in whispers_allowed_groups to post into a topic's staff-only whisper channel. The injected content is visible to whisperers (typically staff) alongside legitimate whispers. Only sites that have whispers enabled are affected. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

Affected products

• Discourse Discourse: before 2026.1.0 (fixed in 2026.1.0); from 2026.1.0, before 2026.1.4 (fixed in 2026.1.4); from 2026.3.0, before 2026.3.1 (fixed in 2026.3.1); from 2026.4.0, before 2026.4.1 (fixed in 2026.4.1); version 2026.5.0 only

Published 2026-06-12. Last modified 2026-06-17.