CVE-2026-27153
Improper Access Control in Discourse Allows Unauthorized DM Export
Publication date: 2026-02-26
Last updated on: 2026-03-02
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| 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 ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Discourse open source discussion platform prior to versions 2025.12.2, 2026.1.1, and 2026.2.0. It involves an overly permissive allowlist in the method `can_export_entity?` used for exporting data. Specifically, moderators could exploit this flaw to export user Chat Direct Messages (DMs) via the CSV export endpoint. Instead of restricting exports to an explicit allowlist of entities, the method allowed exporting any entity that was not explicitly blocked.
How can this vulnerability impact me? :
The vulnerability allows moderators to export user private Chat DMs that they should not have access to. This could lead to unauthorized disclosure of private user communications, potentially compromising user privacy and trust in the platform.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade your Discourse installation 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 immediate and recommended step.