Vulnerability · Published Feb 26, 2026 · Assigned by GitHub_M

CVE-2026-27151Discourse doesn't validate destination topic when moving posts

Low 1.3

In plain English

A low-severity missing 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 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 4.0)1.3Low

Exploit odds (30 days)0.2%top 92.5% 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, the `move_posts` action only checked `can_move_posts?` on the source topic but never validated write permissions on the destination topic. This allowed TL4 users and category group moderators to move posts into topics in categories where they lack posting privileges (e.g., read-only categories or categories with group-restricted write access). 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-862 · Vector: 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

References

https://github.com/discourse/discourse/security/advisories/GHSA-m69h-9m2g-cfgw x_refsource_CONFIRM