CVE-2026-23743
January 28, 2026
Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, permalinks pointing to access-restricted resources (private topics, categories, posts, or hidden tags) were redirecting users to URLs containing the resource slug, even when the user didn't have access to view the resource. This leaked potentially sensitive information (e.g., private topic titles) via the redirect Location header and the 404 page's search box. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.
Affected Packages
https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) =v2026.1.0-latest <v2026.1.0Fix Suggestion:
Update to version v2026.1.0https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v2025.11.0 <v2025.11.2Fix Suggestion:
Update to version v2025.11.2https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v0.8.0 <v3.5.4Fix Suggestion:
Update to version v3.5.4Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Exposure of Sensitive Information to an Unauthorized Actor
EPSS
Base Score:
0.04
