CVE-2026-75025 Mattermost Desktop local network access from server-rendered content

What is CVE-2026-75025?

CVE-2026-75025 is a medium-severity server-side request forgery vulnerability in Mattermost, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Mattermost Desktop App versions <=6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing local or private network resources. Thanks to game0v3r for contributing to this improvement under the Mattermost responsible disclosure policy. Mattermost Advisory ID: MMSA-2026-00698

Weakness: CWE-346

Which versions are affected by CVE-2026-75025?

It affects 1 product.

Products include Mattermost Mattermost Desktop.

How do I fix CVE-2026-75025?

No fix has been published for CVE-2026-75025 yet. Limit exposure of the affected software until one is available.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2026-75025 being exploited?

There is no known exploitation of CVE-2026-75025 in the wild and no public exploit code.

Other vulnerabilities in Mattermost

• CVE-2016-11064 Code injection in n/a Critical 9.8
• CVE-2019-20856 Code injection in n/a Critical 9.8
• CVE-2019-20861 Code injection in n/a High 8.8
• CVE-2026-1046 Arbitrary application execution via unvalidated server-controlled URLs in Help menu High 7.6
• CVE-2020-14456 Security feature bypass in n/a High 7.3

Sources

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

Also known as GHSA-jcpq-22g2-pfpw.