---
id: "CVE-2026-19601"
kind: "vulnerability"
aliases: ["CVE-2026-19601"]
title: "Mattermost: stored AD/LDAP bind password leaks to attacker-chosen server"
severity: "medium"
cvss: 4.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["active-directory", "ldap", "mattermost", "package", "self-hosted"]
not_affected_if: ["auth-required", "managed-hosting", "no-ad-ldap"]
published_at: "2026-10-16T07:17:12+00:00"
first_seen_at: "2026-10-23T21:57:12+00:00"
updated_at: "2026-10-25T04:32:56+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19601", "first_seen_at": "2026-10-23T21:57:12+00:00"}]
---

# Mattermost: stored AD/LDAP bind password leaks to attacker-chosen server

Mattermost keeps the AD/LDAP bind password after other connection settings, such as the server address, are changed. A System Console administrator can then use Test Connection to send that plaintext password to a server they control.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Mattermost server version with `mattermost version` or the System Console version page; affected lines are 11.7.x up to 11.7.10, 11.8.x up to 11.8.5, 11.9.x up to 11.9.1, and 11.10.x up to 11.10.1
- Confirm AD/LDAP is enabled in System Console under Authentication > AD/LDAP

## Fix

- Upgrade Mattermost to a fixed release for your line (unknown exact version in sources; see MMSA-2026-00764)
- Rotate the AD/LDAP bind password after upgrading, since it may already have been exposed

## Timeline

- 2026-10-23T21:57:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-19601

## From the sources

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to invalidate the stored AD/LDAP bind password when other connection settings (such as the server address) are changed, which allows a System Console administrator to disclose the plaintext bind password to an attacker-controlled server via the Test Connection / diagnostics feature. Mattermost Advisory ID: MMSA-2026-00764

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_