CVE-2026-6334

Summary

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermost Advisory ID: MMSA-2026-00570

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost11.5.0 <= 11.5.1affected
MattermostMattermost10.11.0 <= 10.11.13affected
MattermostMattermost11.6.0unaffected
MattermostMattermost11.5.2unaffected
MattermostMattermost10.11.14unaffected

Weaknesses

  • CWE-305: CWE-305 – Authentication Bypass by Primary Weakness

ADP Enrichment

CISA ADP Vulnrichment

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

References