CVE-2025-3228: Unauthorized Guest user access to Playbook

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-20 · updated 2026-06-17
Weakness: CWE-863

Description

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly retrieve requestorInfo from playbooks handler for guest users which allows an attacker access to the playbook run.

Affected products

Mattermost: from 9.11.0 before 9.11.16; from 10.5.0 before 10.5.6; from 10.6.0 before 10.6.6; from 10.7.0 before 10.7.3; 10.8.0, 10.8.0-rc1, 10.8.0-rc2, 10.8.0-rc3 — fixed in 10.5.6, 10.6.6, 10.7.3, 9.11.16

How to fix

Upgrade to a fixed version: Mattermost 10.5.6, 10.6.6, 10.7.3, 9.11.16. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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