Vulnerability · Published Jan 28, 2026 · Assigned by GitHub_M

CVE-2026-23743Discourse allows permalinks to restricted resources to leak resource slugs to unauthorized users

Medium 6.9

In plain English

A medium-severity information exposure in discourse from discourse. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.3%top 78.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
discourse	discourse	< 3.5.4>= 2025.11.0-latest, < 2025.11.2>= 2025.12.0-latest, < 2025.12.1>= 2026.1.0-latest, < 2026.1.0

Weakness: CWE-200 · 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

References

https://github.com/discourse/discourse/security/advisories/GHSA-v5jw-rxc6-4cvv x_refsource_CONFIRM