What is the CVSS score of CVE-2026-26207?

CVE-2026-26207 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Discourse are affected by CVE-2026-26207?

Organizations using Discourse should be aware of moderate risk from CVE-2026-26207, a missing authorization vulnerability rated CVSS 5.4. Attackers could gain access beyond their authorized level.

How to fix or mitigate CVE-2026-26207?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Discourse CVE-2026-26207

MEDIUM

Missing Authorization (CWE-862)

2026-02-26 security-advisories@github.com

Information Disclosure Discourse

5.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.4 MEDIUM

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Feb 26, 2026 - 16:24 nvd

MEDIUM 5.4

DescriptionGitHub Advisory

Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, discourse-policy plugin allows any authenticated user to interact with policies on posts they do not have permission to view. The PolicyController loads posts by ID without verifying the current user's access, enabling policy group members to accept/unaccept policies on posts in private categories or PMs they cannot see and any authenticated user to enumerate which post IDs have policies attached via differentiated error responses (information disclosure). The issue is patched in versions 2025.12.2, 2026.1.1, and 2026.2.0 by adding a guardian.can_see?(@post) check in the set_post before_action, ensuring post visibility is verified before any policy action is processed. As a workaround, disabling the discourse-policy plugin (policy_enabled = false) eliminates the vulnerability. There is no other workaround without upgrading.

AnalysisAI

The discourse-policy plugin in Discourse prior to versions 2025.12.2, 2026.1.1, and 2026.2.0 fails to verify user permissions when processing policy actions, allowing authenticated users to accept or reject policies on posts they cannot access in private categories or private messages. Attackers can exploit this authorization bypass to manipulate policies on restricted content and enumerate post IDs with policies through error message differences. The vulnerability requires authentication but affects the confidentiality and integrity of policy-protected discussions.

Technical ContextAI

Classified as CWE-862 (Missing Authorization). Affects Discourse. Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, discourse-policy plugin allows any authenticated user to interact with policies on posts they do not have permission to view. The PolicyController loads posts by ID without verifying the current user's access, enabling policy group members to accept/unaccept policies on posts in private categories or PMs they cannot see and any authenticated user to enumerate which post IDs have policies att