Auth bypass in Discourse
CVE-2026-27454
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, requesting /posts/:id.json?version=X bypassed authorization checks on post revisions. The display_post method called post.revert_…
Vulnerability class: Broken Access Control
EPSS: 0.001 (17.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Discourse — versions >= 2026.1.0-latest, < 2026.1.2, >= 2026.2.0-latest, < 2026.2.1, = 2026.3.0-latest
Weakness classification (CWE)
References
- https://github.com/discourse/discourse/security/advisories/GHSA-fq69-f929-wp96 (x_refsource_CONFIRM)
- https://github.com/discourse/discourse/commit/8510fde30eb0d7f2dee822a95f6cf43b9ac943d0 (x_refsource_MISC)
- https://github.com/discourse/discourse/commit/c0eeb5892f5d61ad62b057f4d468333a6e9f28c3 (x_refsource_MISC)
- https://github.com/discourse/discourse/commit/c474fbd79d2bd231baafb4332970297d781f92ca (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-27454?
- CVE-2026-27454 is a medium-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-03-19.
- How severe is CVE-2026-27454?
- Medium severity. CVSS v3 base score is 5.3 out of 10.