---
id: CVE-2026-86348
title: >-
  Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover
  from handler panics, which allows an authenticated user to crash the plugin
  via a post-action request with an unexpected field type.
summary: >-
  Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover
  from handler panics, which allows an authenticated user to crash the plugin
  via a post-action request with an unexpected field type.. Mattermost Advisory
  ID: MMSA…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-704
vendor: Mattermost
product: Mattermost
affected:
  - >-
    Mattermost >= <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 <= <=11.9 11.0.9 11.4.8
    11.7.7 10.22.11.0
published: '2026-09-14'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T19:30:49.967'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86348'
references:
  - url: 'https://mattermost.com/security-updates'
    label: responsibledisclosure@mattermost.com
tags:
  - nvd
  - cve.org
epss: 0.00359
epssPercentile: 0.26922
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-14T19:13:36.957049Z'
ingestedAt: '2026-09-14T15:23:07.422Z'
---

## Overview

Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a post-action request with an unexpected field type.. Mattermost Advisory ID: MMSA-2026-00701

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.