CVE-2026-9597 — Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint

CVE-2026-9597

Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint PUBLISHED

Description (CNA)

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.7.0 through 11.7.2; affected 11.6.0 through 11.6.4; unaffected 11.8.0; unaffected 11.7.3; unaffected 11.6.5

CWE

CWE-305

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.