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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
Lifecycle Timeline
6DescriptionGitHub 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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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
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. …
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External POC / Exploit Code
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EUVD-2026-13196