CVE-2025-58084 Mattermost Desktop App crashes when clicking on malformed external URL
An attacker can crash the Mattermost Desktop App by sending a malformed external URL, requiring users to upgrade to a patched version.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-58084?
CVE-2025-58084 is a low-severity denial of service vulnerability in Mattermost, published on 13 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.
Weakness: CWE-1287
Which versions are affected by CVE-2025-58084?
It affects 1 product.
Products include Mattermost Mattermost Desktop.
How do I fix CVE-2025-58084?
No fix has been published for CVE-2025-58084 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-2025-58084 being exploited?
There is no known exploitation of CVE-2025-58084 in the wild and no public exploit code.
Other vulnerabilities in Mattermost
Sources
Also known as GHSA-c8m2-cx6j-jf7p.