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.

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: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

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

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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

CVSS VectorGitHub Advisory

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

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

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

2026.1.2,2026.2.1

EUVD ID Assigned

Mar 19, 2026 - 22:00 euvd

EUVD-2026-13196

Analysis Generated

Mar 19, 2026 - 22:00 vuln.today

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.

AnalysisAI

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.

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Risk assessment & exploitation conditions
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

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

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 AssessmentAI

Exploitation	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. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	Exposed information (credentials, internal paths, user data, configuration) can be leveraged for further attacks or regulatory violations. Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker triggers error conditions or accesses improperly protected endpoints to extract sensitive internal information from the application.
Remediation	Implement proper access controls. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours: Identify all Discourse instances in production and their current versions. …

Threat intelligence, references, and detailed analysis are available after sign-in.

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CVE-2026-27934 vulnerability details – vuln.today

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