CVE-2025-41436 Unauthorized access to archived channel content via threads interface

What is CVE-2025-41436?

CVE-2025-41436 is a low-severity missing authorization vulnerability in Mattermost Mattermost Server, published on 14 Nov 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost versions <11.0 fail to properly enforce the "Allow users to view archived channels" setting which allows regular users to access archived channel content and files via the "Open in Channel" functionality from followed threads

Weakness: CWE-863

Which versions are affected by CVE-2025-41436?

8 open source packages ship an affected version, including github.com/mattermost/mattermost-server, github.com/mattermost/mattermost-server/v5 and github.com/mattermost/mattermost-server/v6. It affects 1 product.

Products include Mattermost Mattermost Server.

How do I fix CVE-2025-41436?

Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 11.0.0-alpha.1 or 11.0.0-alpha.1+incompatible.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2025-41436 being exploited?

There is no known exploitation of CVE-2025-41436 in the wild and no public exploit code.

Other vulnerabilities in Mattermost Mattermost Server

• CVE-2025-12419 Account takeover on OAuth/OpenID-enabled servers Critical 9.9
• CVE-2025-12421 Account Takeover via Code Exchange Endpoint Critical 9.9
• CVE-2025-4981 Path Traversal Leading to RCE by Any Authenticated Mattermost User Critical 9.9
• CVE-2025-20051 Arbitrary file read via block duplication in Mattermost Boards Critical 9.9
• CVE-2025-25279 Arbitrary file read in Mattermost Boards via import & export board archive Critical 9.9

All Mattermost Mattermost Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-x3hx-ch7p-8xgg, GO-2025-4131, MINI-c8pg-wrvp-qccw.