CVE-2026-1046 PUBLISHED

Arbitrary application execution via unvalidated server-controlled URLs in Help menu

Assigner: Mattermost
Reserved: 16.01.2026 Published: 16.02.2026 Updated: 16.02.2026

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

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L
CVSS Score: 7.6

Product Status

Vendor Mattermost
Product Mattermost
Versions Default: unaffected
  • affected from 0 to 6.2.0 (incl.)
  • affected from 0 to 5.2.13 (incl.)
  • Version 6.1.0 is unaffected
  • Version 6.0.3.0 is unaffected
  • Version 5.13.3.0 is unaffected

Solutions

Update Mattermost Desktop App to versions 6.1.0, 6.0.3.0, 5.13.3.0 or higher.

Credits

  • hackerman70000 finder

References

Problem Types

  • CWE-939: Improper Authorization in Handler for Custom URL Scheme CWE