CVE-2026-84302
Deferred Deferred - Pending Action

Information Disclosure in Discourse AI Review Queue

Publication date: 2026-09-24

Last updated on: 2026-09-24

Assigner: GitHub, Inc.

Description
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did not restrict private-message reviewables to the audience permitted to access the underlying private-message topic, allowing the moderator to read otherwise confidential content. Depending on the available reviewable action, the moderator could also modify the private message by closing its topic or deleting a post. Exploitation requires an authenticated moderator account and a pre-existing Discourse AI reviewable associated with a private message. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

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Meta Information

Published
2026-09-24
Last Modified
2026-09-24
Generated
2026-10-15
AI Q&A
2026-09-24
EPSS Evaluated
2026-10-13
NVD
CVE-2026-84302
EUVD
EUVD-2026-86297

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
discourse discourse 2026.1.6
discourse discourse 2026.5.2
discourse discourse 2026.6.1
discourse discourse 2026.7.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

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Executive Summary

This vulnerability in Discourse allows moderators who are not participants in a private message (PM) to view, edit, or delete the PM's content if Discourse AI generates a reviewable associated with that message. The issue occurs because reviewable visibility filtering did not restrict PM reviewables to authorized participants, exposing confidential content to unauthorized moderators.

Detection Guidance

This vulnerability requires checking Discourse AI reviewable access controls. Review Discourse logs for unauthorized moderator actions on private message reviewables. Check for moderators accessing review queues outside their permitted scope. Verify that only participating moderators or admins can view private message reviewables in the system.

Impact Analysis

If you are a user of a Discourse forum, this vulnerability could lead to unauthorized moderators accessing your private messages. This may result in exposure of sensitive or confidential information, potential modification or deletion of your private messages, and a breach of privacy within the platform.

Compliance Impact

This vulnerability could violate privacy regulations like GDPR and HIPAA by allowing unauthorized access to private message content. Organizations using Discourse may face compliance risks, legal penalties, and reputational damage due to the exposure of confidential user data.

Mitigation Strategies

Update Discourse to versions 2026.1.6, 2026.5.2, 2026.6.1, or 2026.7.0 or later to patch the vulnerability. This ensures reviewable visibility filtering restricts private message access to authorized participants only.

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