Skip to content
CVE PROGRAM SOURCE RECORD4.3 Medium

CVE-2026-10103

Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Mattermost

Description

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mattermost Mattermost

Default version status: unaffected

  • 11.7.0 to ≤ 11.7.2affected
  • 11.6.0 to ≤ 11.6.4affected
  • 10.11.0 to ≤ 10.11.19affected
  • 11.8.0unaffected
  • 11.7.3unaffected
  • 11.6.5unaffected
  • 10.11.20unaffected

References