CVE-2026-26230

Summary

Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost10.11.0 <= 10.11.10affected
MattermostMattermost11.4.0unaffected
MattermostMattermost10.11.11unaffected

Weaknesses

  • CWE-863: CWE-863: Incorrect Authorization

ADP Enrichment

CISA ADP Vulnrichment

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

References