Vulnerability · Published Feb 26, 2026 · Assigned by GitHub_M

CVE-2026-28227Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category

Low 1.2

In plain English

A low-severity incorrect authorization 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 3.3% (higher than 88% of all known vulnerabilities).

Severity (CVSS 4.0)1.2Low

Exploit odds (30 days)3.3%top 11.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, TL4 users can publish topics into staff-only categories via the `publish_to_category` topic timer, bypassing authorization checks. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.

Affected products (as reported)

Vendor	Product	Versions
discourse	discourse	< 2025.12.2>= 2026.1.0-latest, < 2026.1.1>= 2026.2.0-latest, < 2026.2.0

Weakness: CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U

References

https://github.com/discourse/discourse/security/advisories/GHSA-m49w-78mh-87jp x_refsource_CONFIRM