What is the CVSS score of CVE-2026-27934?

CVE-2026-27934 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2026-27934?

Yes, a public proof-of-concept exploit is available for CVE-2026-27934. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-27934?

Within 24 hours: Identify all Discourse instances in production and their current versions. Within 7 days: Upgrade to patched versions (2026.3.0-latest.1, 2026.2.1, or 2026.1.2 depending on your current release track). Within 30 days: Audit API access logs to identify potential unauthorized information access and review restricted post content for exposure scope.

Discourse CVE-2026-27934

Q: Which versions of Discourse are affected by CVE-2026-27934?

Discourse discussion platform versions before 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain an information disclosure vulnerability that allows unauthenticated users to access restricted post…. A patch is available.

EUVD-2026-13196 HIGH

Insertion of Sensitive Information Into Sent Data (CWE-201)

2026-03-19 GitHub_M

Information Disclosure Discourse

8.7

CVSS 4.0 · GitHub Advisory

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Send unauthenticated request to user action API
Exploit

Bypass visibility checks on endpoint
Execution

Retrieve private post titles and excerpts
Impact

Access sensitive information disclosure

Vulnerability Assessment

Weakness	CWE CWE-201 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V14 - Data Protection Outbound data filtering
Exploitation Conditions	Remote unauthenticated attacker can call a user action API endpoint in Discourse versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 to disclose private post titles and excerpts. No user interaction required.
Impact	Exposed information (credentials, internal paths, user data, configuration) can be leveraged for further attacks or regulatory violations.
Exploit ScenarioDerived	An attacker triggers error conditions or accesses improperly protected endpoints to extract sensitive internal information from the application.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 19, 2026

Unauthorized information disclosure in Discourse discussion platform versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 allows unauthenticated attackers to view restricted post titles and excerpts through inadequate permission validation on user action API endpoints. The vulnerability affects all deployments running vulnerable versions, with no available workarounds until patching to the fixed releases.

Earlier versions of this analysis (1)

v1 Mar 19, 2026 - 22:00 CVSS 8.7

RemediationAI

Implement proper access controls. Sanitize error messages in production. Review logging practices to avoid capturing sensitive data.

Affected VersionsENISA

discourse 2026.1.0-latest, < 2026.1.2

discourse = 2026.3.0-latest

discourse 2026.2.0-latest, < 2026.2.1

Affected Packages

euvd discourse no fix

euvd discourse_2026_1_0_latest fix: 2026.1.2

euvd discourse_2026_2_0_latest fix: 2026.2.1

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 3 packages in euvd

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

Technical ContextAI · show details

Information disclosure occurs when an application inadvertently reveals sensitive data to unauthorized actors through error messages, logs, or improper access controls.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 8.7 HIGH

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

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

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

High

Vulnerable system: Integrity

None

Vulnerable system: Availability

None

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 06:20 EUVD-patch-fix

executive summary

Patch available

Apr 16, 2026 - 05:29 EUVD

2026.1.2,2026.2.1

CVE Published

Mar 19, 2026 - 21:17 nvd

HIGH 8.7

DescriptionGitHub Advisory

Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a lack of visibility checks with a user action API endpoint that results in disclosure of the title and post excerpt to unauthorized users, leading to information disclosure. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

Executive ViewAI

Why It Matters

Discourse discussion platform versions before 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain an information disclosure vulnerability that allows unauthenticated users to access restricted post titles and excerpts through API endpoints, exposing confidential discussions across all affected deployments without authentication requirements.

Business Impact: High

Compensating Controls

Apply vendor patch to versions 2026.3.0-latest.1, 2026.2.1, or 2026.1.2.

Threat Intelligence Overview

EPSS Score

0.0%

Top 87% exploitable

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS POC (1)

GitHub

VulDB

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 HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

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

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +44

PoC: +20

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.