VULNERABILITY INTELLIGENCE
CVE-2026-21865
CVSS score6.5 MEDIUM
EPSS probability0.26%
CISA KEVNot currently listed
Published2026-01-28
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
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.
Weakness classification
- security-advisories@github.com: CWE-862
Primary references
- security-advisories@github.com — Third Party Advisory