Vulnerability · Published Feb 16, 2026 · Assigned by Mattermost
CVE-2026-1046Arbitrary application execution via unvalidated server-controlled URLs in Help menu
High 7.6
In plain English
A high-severity security flaw in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).
Severity (CVSS 3.1)7.6High
Exploit odds (30 days)0.3%top 82.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
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
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 0 – through 6.2.00 – through 5.2.13 |
Weakness: CWE-939 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L
References
- MMSA-2026-00577 vendor-advisory