Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Lifecycle Timeline
6DescriptionGitHub Advisory
Discourse is an open-source discussion platform. The visibility of posts typed whisper is controlled via the whispers_allowed_groups site setting. Only users that belong to groups specified in the site setting are allowed to view posts typed whisper. However, it has been discovered that users of versions prior to 3.4.6 on the stable branch and prior to 3.5.0.beta8-dev on the tests-passed branch can continue to see their own whispers even after losing visibility of posts typed whisper. This issue is patched in versions 3.4.6 and 3.5.0.beta8-dev. No known workarounds are available.
AnalysisAI
Discourse versions prior to 3.4.6 (stable) and 3.5.0.beta8-dev (tests-passed) contain an information disclosure vulnerability where users retain visibility of their own whisper-typed posts even after losing group membership that should restrict access to whispers. This is a logic flaw in the whisper visibility enforcement mechanism (CWE-200: Information Exposure) affecting unauthenticated network access with high confidentiality impact. No public exploitation has been reported, but the issue is easily discoverable through normal platform usage.
Technical ContextAI
Discourse is an open-source discussion platform that implements a whisper post type—a feature allowing posts visible only to specified groups via the whispers_allowed_groups site setting. The vulnerability stems from insufficient visibility control logic (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) where the authorization check fails to properly enforce group membership restrictions on historical whisper posts owned by the user. The root cause appears to be a gap in re-evaluating post visibility permissions when group membership changes, allowing users to retain access to previously authored whispers despite no longer belonging to authorized groups. The affected products are Discourse instances (CPE pattern: cpe:2.3:a:discourse:discourse:*) running versions 3.4.x prior to 3.4.6 and 3.5.0.beta versions prior to beta8-dev.
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External POC / Exploit Code
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EUVD-2025-19108