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.
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:*:*:*
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}


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 22:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 28 Jan 2026 20:30:00 +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, 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.
Title Discourse allows permalinks to restricted resources to leak resource slugs to unauthorized users
Weaknesses CWE-200
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-28T20:07:21.266Z

Updated: 2026-01-28T21:07:37.739Z

Reserved: 2026-01-15T15:45:01.958Z

Link: CVE-2026-23743

cve-icon Vulnrichment

Updated: 2026-01-28T20:53:02.503Z

cve-icon NVD

Status : Analyzed

Published: 2026-01-28T21:16:11.597

Modified: 2026-01-30T20:31:49.593

Link: CVE-2026-23743

cve-icon Redhat

No data.