CVE-2026-27491 MEDIUM

CVE-2026-27491: Discourse has a bypass of official warnings messages by non-staff users

Vendor Discourse
Product discourse
Weakness CWE-862 · Missing authorization
Published March 19, 2026
Last update March 20, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 19, 2026 CVE published
March 20, 2026 Record updated

Related vulnerabilities

04Related CVE