---
id: CVE-2026-9597
title: >-
  Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether
  a guest account is deactivated before creating a session in the magic-link
  token login path, which allows a deactivated guest user to obtain a fully
  functional…
summary: >-
  Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether
  a guest account is deactivated before creating a session in the magic-link
  token login path, which allows a deactivated guest user to obtain a fully
  functional…
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-305
published: '2026-07-13'
updated: '2026-07-13'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-9597'
references:
  - url: 'https://mattermost.com/security-updates'
    label: responsibledisclosure@mattermost.com
tags:
  - nvd
ingestedAt: '2026-07-13T12:26:58.176Z'
epss: 0.0023
epssPercentile: 0.12297
---

## Overview

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681

## Remediation

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