CVE-2025-24526 Channel export permitted on archived channel when viewing archived channels is disabled

Medium 4.3 Published Updated

Attackers can export archived channel contents despite disabled viewing permissions, leading to unauthorized data disclosure in Mattermost.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2025-24526?

CVE-2025-24526 is a medium-severity missing authorization vulnerability in Mattermost Mattermost Server, published on 24 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost versions 10.1.x <= 10.1.3, 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to restrict channel export of archived channels when the "Allow users to view archived channels" is disabled which allows a user to export channel contents when they shouldn't have access to it

Weakness: CWE-863

Which versions are affected by CVE-2025-24526?

14 open source packages ship an affected version, including github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server and github.com/mattermost/mattermost-server/v5. It affects 1 product.

PackageAffectedFixed in
github.com/mattermost/mattermost/server/v8 GoAll versions8.0.0-20250110161910-96195f1bd746
github.com/mattermost/mattermost/server/v8 GoAll versions8.0.0-20250110161910-96195f1bd746
github.com/mattermost/mattermost/server/v8 GoAll versions8.0.0-20250110161910-96195f1bd746
github.com/mattermost/mattermost/server/v8 GoFrom 10.2.0-rc110.2.3
github.com/mattermost/mattermost/server/v8 GoFrom 10.2.0-rc110.2.3
github.com/mattermost/mattermost/server/v8 GoFrom 10.3.0-rc110.3.3
8 more packages
github.com/mattermost/mattermost/server/v8 GoFrom 10.3.0-rc110.3.3
github.com/mattermost/mattermost/server/v8 GoFrom 10.4.0-rc110.4.2
github.com/mattermost/mattermost/server/v8 GoFrom 10.4.0-rc110.4.2
github.com/mattermost/mattermost/server/v8 GoFrom 9.11.0-rc19.11.8
github.com/mattermost/mattermost/server/v8 GoFrom 9.11.0-rc19.11.8
github.com/mattermost/mattermost-server GoFrom 9.11.0-rc1+incompatible9.11.8+incompatible, 10.2.3+incompatible, 10.3.3+incompatible, 10.4.2+incompatible
github.com/mattermost/mattermost-server/v5 GoAll versionsNone
github.com/mattermost/mattermost-server/v6 GoAll versionsNone

Products include Mattermost Mattermost Server.

How do I fix CVE-2025-24526?

Upgrade github.com/mattermost/mattermost/server/v8 to a fixed version for your release line: 8.0.0-20250110161910-96195f1bd746, 10.2.3, 10.3.3 or 10.4.2.

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

Is CVE-2025-24526 being exploited?

There is no known exploitation of CVE-2025-24526 in the wild and no public exploit code.

All Mattermost Mattermost Server vulnerabilities

Sources

Also known as GHSA-q8p2-2hwc-jw64, GO-2025-3481.

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