CVE-2026-59830

Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action descriptions. Viewing the affected user activity streams could execute attacker-controlled script in another user's browser. This issue is fixed in version 2026.7.0.

• https://github.com/discourse/discourse/commit/dd786594ddd088657a7e6f9fefba5bd889965fe4
• https://github.com/discourse/discourse/releases/tag/v2026.7.0
• https://github.com/discourse/discourse/security/advisories/GHSA-x6mf-p7cg-69rw