CVE-2026-27151CWE-862

Discourse doesn't validate destination topic when moving posts

Low · published February 26, 2026

CVSS v4.0
1.3
EPSS
0%
Percentile
18.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
1.3 · LOW
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
EPSS
0.00274 · 18.7th percentile
Weakness
CWE-862 · Missing Authorization
Published
2026-02-26T19:57Z
EPSS history
Timeline
  • 26 FEB 19:57Z
    Discourse doesn't validate destination topic when moving posts
    cvelistv5