CVE-2026-12284

Summary

Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost0 <= 6.2.2affected
MattermostMattermost6.3.0unaffected
MattermostMattermost6.2.3.0unaffected

Weaknesses

  • CWE-346: CWE-346: Origin Validation Error

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References