CVE-2026-1046 Arbitrary application execution via unvalidated server-controlled URLs in Help menu
A malicious server can execute arbitrary code on a user's system by providing unvalidated URLs in the Help menu of the Mattermost Desktop App.
- 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-2026-1046?
CVE-2026-1046 is a high-severity command injection vulnerability in Mattermost, published on 16 Feb 2026. 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 <=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost server to execute arbitrary executables on a user’s system via the user clicking on certain items in the Help menu Mattermost Advisory ID: MMSA-2026-00577
Weakness: CWE-939
Which versions are affected by CVE-2026-1046?
It affects 1 product.
Products include Mattermost Mattermost Desktop.
How do I fix CVE-2026-1046?
No fix has been published for CVE-2026-1046 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-1046 being exploited?
There is no known exploitation of CVE-2026-1046 in the wild and no public exploit code.
Other vulnerabilities in Mattermost
Sources
Also known as GHSA-gjx5-j34g-5g5p.