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_to directly without verifying whether the revision was hidden or if the user had permission to view edit history. This meant hidden revisions (intentionally concealed by staff) could be read by any user by simply enumerating version numbers. Starting in versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, Discourse looks up the PostRevision and call guardian.ensure_can_see! before reverting, consistent with how the /posts/:id/revisions/:revision endpoint already authorizes access. No known workarounds are available.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/discourse/discourse/commit/8510fde30eb0d7f2dee822a95f6cf43b9ac943d0	Patch
https://github.com/discourse/discourse/commit/c0eeb5892f5d61ad62b057f4d468333a6e9f28c3	Patch
https://github.com/discourse/discourse/commit/c474fbd79d2bd231baafb4332970297d781f92ca	Patch
https://github.com/discourse/discourse/security/advisories/GHSA-fq69-f929-wp96	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:discourse:discourse::::::::
	cpe:2.3:a:discourse:discourse::::::::
	cpe:2.3:a:discourse:discourse:2026.3.0::::latest:::

History

No history.

Information

Published : 2026-03-19 21:17

Updated : 2026-03-25 01:01

NVD link : CVE-2026-27454

Mitre link : CVE-2026-27454

CVE.ORG link : CVE-2026-27454

JSON object : View

Products Affected

discourse

discourse

CWE

CWE-862

Missing Authorization

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