CVE-2026-6334 — OAuth authorization code client binding not enforced during token redemption in Mattermost

CVE-2026-6334

OAuth authorization code client binding not enforced during token redemption in Mattermost PUBLISHED

Description (CNA)

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 (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.5.0 through 11.5.1; affected 10.11.0 through 10.11.13; unaffected 11.6.0; unaffected 11.5.2; unaffected 10.11.14

CWE

CWE-305

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.