Discourse 2026.1.5 Review Queue Exposes PM Excerpts to Unauthorized Mods
CVE-2026-59829 Published on August 17, 2026
Discourse: Review queue exposes flag-related private message excerpts to category group moderators
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.
Vulnerability Analysis
CVE-2026-59829 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is an AuthZ Vulnerability?
The software does not perform an authorization check when an actor attempts to access a resource or perform an action.
CVE-2026-59829 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-59829
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Affected Versions
discourse:- Version >= 2026.1.0-latest, < 2026.1.6 is affected.
- Version >= 2026.5.0-latest, < 2026.5.2 is affected.
- Version < 2026.6.1 is affected.