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.
History

Wed, 23 Sep 2026 03:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 21 Sep 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Discourse
Discourse discourse
Vendors & Products Discourse
Discourse discourse

Mon, 21 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Discourse: Stored XSS via unescaped actor name in post actions
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-21T21:17:38.733Z

Updated: 2026-09-22T15:38:41.155Z

Reserved: 2026-07-07T15:00:50.979Z

Link: CVE-2026-59830

cve-icon Vulnrichment

Updated: 2026-09-22T14:12:12.965Z

cve-icon NVD

Status : Deferred

Published: 2026-09-21T22:16:57.353

Modified: 2026-09-23T17:17:50.143

Link: CVE-2026-59830

cve-icon Redhat

No data.