Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, moderators can convert some personal messages to public topics when they shouldn't have access. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, site admin can temporarily revoke the moderation role from untrusted moderators or remove the moderator group from the "personal message enabled groups" site setting until the Discourse instance has been upgraded to a version that has been patched.
History

Fri, 30 Jan 2026 20:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*
cpe:2.3:a:discourse:discourse:2025.12.0:*:*:*:stable:*:*:*
cpe:2.3:a:discourse:discourse:2026.1.0:*:*:*:stable:*:*:*

Thu, 29 Jan 2026 10:15:00 +0000

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

Wed, 28 Jan 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Wed, 28 Jan 2026 20:00:00 +0000

Type Values Removed Values Added
Description Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, moderators can convert some personal messages to public topics when they shouldn't have access. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, site admin can temporarily revoke the moderation role from untrusted moderators or remove the moderator group from the "personal message enabled groups" site setting until the Discourse instance has been upgraded to a version that has been patched.
Title Discourse topic conversion permission vulnerability for moderators
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-28T19:51:37.991Z

Updated: 2026-01-28T20:10:06.915Z

Reserved: 2026-01-05T16:44:16.368Z

Link: CVE-2026-21865

cve-icon Vulnrichment

Updated: 2026-01-28T20:09:49.084Z

cve-icon NVD

Status : Analyzed

Published: 2026-01-28T20:16:14.530

Modified: 2026-01-30T20:30:18.947

Link: CVE-2026-21865

cve-icon Redhat

No data.