CVE-2026-59829
Received Received - Intake

Information Disclosure in Discourse Review Queue

Publication date: 2026-08-17

Last updated on: 2026-08-17

Assigner: GitHub, Inc.

Description
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt (and permalink) of the private message attached to a flag, even when the reviewing category moderator was not a participant in that message. These notify_moderators flag messages are addressed only to moderators and, for core flags, to a category's moderation groups as they existed when the flag was raised, so a category group moderator could read flag-discussion content they were not authorized to see. This affects official plugins that create such messages and core flags raised before a moderator's group was granted moderation of the category. Only the confidentiality of a limited excerpt of these flag-related private messages is affected; no content can be modified or deleted. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1.

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Meta Information

Published
2026-08-17
Last Modified
2026-08-17
Generated
2026-08-17
AI Q&A
2026-08-17
EPSS Evaluated
N/A
NVD
CVE-2026-59829
EUVD
EUVD-2026-60235

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
discourse discourse to 2026.1.6 (exc)
discourse discourse 2026.1.6
discourse discourse 2026.5.2
discourse discourse 2026.6.1
discourse discourse 2026.7.1

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

CVE-2026-59829 is a vulnerability in Discourse where category moderators could view private message excerpts related to flag discussions in the review queue, even if they were not intended recipients. This happened when category group moderation was enabled, exposing sensitive flag-related private messages meant only for specific moderators or staff.

Detection Guidance

To detect this vulnerability, check if your Discourse instance is running an affected version (before 2026.1.6, 2026.5.2, 2026.6.1, or 2026.7.1). Verify if category group moderation is enabled by inspecting site settings. Look for unauthorized access to private message excerpts in review queues.

Impact Analysis

The vulnerability could lead to unauthorized disclosure of sensitive moderation discussions, including private flag reasons or other confidential information. While it does not allow modification or deletion of content, it compromises the confidentiality of limited excerpts of private messages in the review queue.

Compliance Impact

This vulnerability could potentially violate compliance with GDPR and HIPAA by exposing private message excerpts related to moderation flags to unauthorized category moderators. Unauthorized access to sensitive moderation discussions may result in breaches of confidentiality requirements for personal or health data.

Mitigation Strategies

Upgrade Discourse to a patched version (2026.1.6, 2026.5.2, 2026.6.1, or 2026.7.1) immediately. As a temporary workaround, disable the enable_category_group_moderation site setting until patched.

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