CVE-2025-31947: Repeated LDAP login failures can lock an LDAP account

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-15 · updated 2026-06-17
Weakness: CWE-645

Description

Mattermost versions 10.6.x <= 10.6.1, 10.5.x <= 10.5.2, 10.4.x <= 10.4.4, 9.11.x <= 9.11.11 fail to lockout LDAP users following repeated login failures, which allows attackers to lock external LDAP accounts through repeated login failures through Mattermost.

Affected products

Mattermost: from 9.11.0 before 9.11.12; from 10.4.0 before 10.4.5; from 10.5.0 before 10.5.3; from 10.6.0 before 10.6.2 — fixed in 10.4.5, 10.5.3, 10.6.2, 9.11.12

How to fix

Upgrade to a fixed version: Mattermost 10.4.5, 10.5.3, 10.6.2, 9.11.12. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

Get alerted when CVE-2025-31947 or the next vulnerability affects your stack