CVE-2026-27152
Received Received - Intake
DM Communication-Preference Bypass in Discourse Allows Unauthorized Messaging

Publication date: 2026-02-26

Last updated on: 2026-03-02

Assigner: GitHub, Inc.

Description
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, DM communication-preference bypass when adding members via `Chat::AddUsersToChannel` — a user could add targets who have blocked/ignored/muted them to an existing DM channel, bypassing per-recipient PM restrictions that are enforced during DM channel creation. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
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Meta Information
Published
2026-02-26
Last Modified
2026-03-02
Generated
2026-06-16
AI Q&A
2026-02-26
EPSS Evaluated
2026-06-14
NVD
CVE-2026-27152
EUVD
EUVD-2026-8891
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
discourse discourse to 2025.12.2 (exc)
discourse discourse From 2026.1.0 (inc) to 2026.1.1 (exc)
discourse discourse 2026.2.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-284 The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
Attack-Flow Graph
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Executive Summary

CVE-2026-27152 is a vulnerability in the Discourse open source discussion platform that allows a user to bypass direct message (DM) communication preferences. Specifically, when adding members to an existing DM channel using the Chat::AddUsersToChannel function, a user can add targets who have blocked, ignored, or muted them. This bypass circumvents the per-recipient private message restrictions that are normally enforced during the creation of DM channels.

Impact Analysis

This vulnerability can impact users by allowing unwanted communication despite their preferences to block, ignore, or mute certain users. Attackers can add users who have blocked them into existing DM channels, potentially exposing users to unwanted messages or interactions that they intended to avoid. This improper access control could lead to privacy concerns and a degraded user experience.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

The recommended immediate step to mitigate this vulnerability is to upgrade the Discourse software to one of the patched versions: 2025.12.2, 2026.1.1, or 2026.2.0.

No known workarounds are available, so applying the update is the primary method to address the issue.

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