Low severity · published Feb 26, 2026
CVE-2026-27151
Discourse doesn't validate destination topic when moving posts
2.7
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DI
discourse · discourse
< 2025.12.2; >= 2026.1.0-latest, < 2026.1.1; >= 2026.2.0-latest, < 2026.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27151
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27151
Vendor Advisory
https://github.com/discourse/discourse/security/advisories/GHSA-m69h-9m2g-cfgw
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