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%.

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

View

Vulnerability Assessment

Weakness	CWE CWE-862 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V8 - Authorization Authorization checks on every request MITRE ATT&CK 1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS 5.4 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: None. Exploitation requires authentication.
Exploit ScenarioDerived	An attacker (requires authentication) could exploit this vulnerability to compromise the affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

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.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 5.4

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

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

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Exploit and PoC references, threat intelligence from 22 sources

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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

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.

Executive ViewAI

Why It Matters

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. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Low

Compensating Controls

Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.

Threat Intelligence Overview

EPSS Score

0.0%

Top 92% exploitable

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC No

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Defer

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +27

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.