Vulnerability Description
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, a type coercion issue in a post actions API endpoint allowed non-staff users to issue warnings to other users. Warnings are a staff-only moderation feature. The vulnerability required the attacker to be a logged-in user and to send a specifically crafted request. No data exposure or privilege escalation beyond the ability to create unauthorized user warnings was possible. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse | >= 2026.1.0, < 2026.1.2 |
Related Weaknesses (CWE)
References
- https://github.com/discourse/discourse/commit/60a588f4da4ab0feceb2c44787d4261b4fPatch
- https://github.com/discourse/discourse/commit/d3cb203feabc46d765ecb91f348613a2bdPatch
- https://github.com/discourse/discourse/commit/f5fef73827da7520efc517357bd2a6bab3Patch
- https://github.com/discourse/discourse/security/advisories/GHSA-xq37-5fvf-4m4jVendor Advisory
FAQ
What is CVE-2026-27491?
CVE-2026-27491 is a vulnerability with a CVSS score of 4.3 (MEDIUM). Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, a type coercion issue in a post actions API endpoint allowed non-staff users to issue warn...
How severe is CVE-2026-27491?
CVE-2026-27491 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-27491?
Check the references section above for vendor advisories and patch information. Affected products include: Discourse Discourse.