CVE-2024-29215: Slash commands run in channel without channel membership via playbook task commands

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-26 · updated 2026-06-17
Weakness: CWE-284

Description

Mattermost versions 9.5.x <= 9.5.3, 9.7.x <= 9.7.1, 9.6.x <= 9.6.1, 8.1.x <= 8.1.12 fail to enforce proper access control which allows a user to run a slash command in a channel they are not a member of via linking a playbook run to that channel and running a slash command as a playbook task command.

Affected products

Mattermost: from 8.1.0 before 8.1.13; from 9.5.0 before 9.5.4; from 9.6.0 before 9.6.2; from 9.7.0 before 9.7.2 — fixed in 8.1.13, 9.5.4, 9.6.2, 9.7.2

How to fix

Upgrade to a fixed version: Mattermost 8.1.13, 9.5.4, 9.6.2, 9.7.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-29215 or the next vulnerability affects your stack