PatchTheCVECVE-2026-13411: Mattermost versions 11.7.x <= 11.7.11 fail to validate null elements when decoding playbook import conditions
21
Routine
MEDIUM 4.3
CVE-2026-13411 is a medium-severity flaw (CVSS 4.3) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Mattermost versions 11.7.x <= 11.7.11 fail to validate null elements when decoding playbook import conditions which allows an authenticated attacker to crash the Playbooks plugin instance-wide via a crafted import request containing a null condition. Mattermost Advisory ID: MMSA-2026-00709
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 4.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 76%) |
| CISA exploited list | No |
| Weakness | CWE-754 |
| Published | 2026-10-22 |
| Last modified | 2026-10-22 |
Publisher (CNA): Mattermost, Inc.
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.