CVE-2026-3433 — Mattermost fails to scope role_updated websocket events to authorized team and channel members

Description (CNA)

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to restrict role_updated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with guest-level access to observe permission scheme change notifications for private teams they are not a member of via the websocket connection.. Mattermost Advisory ID: MMSA-2026-00616

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.6.0 through 11.6.1; affected 11.5.0 through 11.5.4; affected 10.11.0 through 10.11.15; affected 10.11.0 through 10.11.16; unaffected 11.7.0; unaffected 11.6.2; unaffected 11.5.5; unaffected 10.11.16; unaffected 10.11.17

CWE

CWE-200

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.