CVE-2025-21083 Insufficient Input Validation on Post Props

Q: Is CVE-2025-21083 being exploited?

There is no known exploitation of CVE-2025-21083 in the wild and no public exploit code.

Q: How do I fix CVE-2025-21083?

No fix has been published for CVE-2025-21083 yet. Limit exposure of the affected software until one is available.

Medium 6.5 Published 15 Jan 2025 Updated 15 Jan 2025

A malicious authenticated user can crash the Mattermost mobile app by sending a post with improperly validated properties.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-21083?

CVE-2025-21083 is a medium-severity denial of service vulnerability in Mattermost, published on 15 Jan 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost Mobile Apps versions <=2.22.0 fail to properly validate post props which allows a malicious authenticated user to cause a crash via a malicious post.

Weakness: CWE-1287

Which versions are affected by CVE-2025-21083?

It affects 1 product.

Products include Mattermost Mattermost Mobile.

How do I fix CVE-2025-21083?

No fix has been published for CVE-2025-21083 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-21083 being exploited?

There is no known exploitation of CVE-2025-21083 in the wild and no public exploit code.

Sources

Also known as GHSA-h8hh-7xxw-q4pg.