Missing Authorization in Discourse - CVE-2026-27151
Published: July 1, 2026
Vulnerability identifier: #VU136116
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-27151
CWE-ID: CWE-862
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote user to bypass authorization checks.
The vulnerability exists due to improper access control in the move_posts action when moving posts between topics. A remote user can move posts into a destination topic without having write permissions there to bypass authorization checks.
This affects TL4 users and category group moderators, including cases involving read-only categories or categories with group-restricted write access.
How to mitigate CVE-2026-27151
Install security update from vendor's website.