---
id: "CVE-2026-121638"
kind: "vulnerability"
aliases: ["CVE-2026-121638"]
title: "WatchGuard AuthPoint Gateway before 7.6.0: improper certificate validation allows man-in-the-middle attacks"
severity: "critical"
cvss: 9.1
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "AuthPoint Gateway", "fixed": ["7.6.0"], "affected": ">= 1.0, < 7.6.0", "ecosystem": "vendor"}]
ecosystems: []
tags: ["authentication", "authpoint", "infrastructure", "mfa", "mitm", "self-hosted", "watchguard", "windows"]
not_affected_if: ["no-authpoint-gateway"]
published_at: "2026-11-04T15:17:42+00:00"
first_seen_at: "2026-11-04T15:27:30+00:00"
updated_at: "2026-11-04T15:30:10+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121638", "first_seen_at": "2026-11-04T15:27:30+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-04T15:30:10+00:00"}]
---

# WatchGuard AuthPoint Gateway before 7.6.0: improper certificate validation allows man-in-the-middle attacks

WatchGuard AuthPoint Gateway does not properly validate certificates when talking to local authentication providers. An attacker on the network path can intercept and modify that traffic.

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

## Affected

- vendor:AuthPoint Gateway affected >= 1.0, < 7.6.0 fixed 7.6.0

## How to check

Find your installed WatchGuard AuthPoint Gateway version (Windows Server host running the Gateway service; also shown in the AuthPoint management console under Gateways). Any version from 1.0 up to but not including 7.6.0 is affected. Per-CVE advisory text was not readable; only the vendor listing's version range was.

## Fix

Upgrade AuthPoint Gateway to 7.6.0 or later (released 29 Oct 2026).

## Timeline

- 2026-11-04T15:27:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121638
- 2026-11-04T15:30:10+00:00 analyst — WatchGuard PSIRT listing (CVSS 9.1, published 2026-11-04) gives affected >=1.0,<7.6.0, fixed 7.6.0; release notes confirm Gateway 7.6.0 on 29 Oct 2026 (they say only 'resolved a security vulnerability', not tied to this CVE). Per-CVE advisory page not retrievable, so no detail on attack preconditions; no exploitation info seen. Siblings: CVE-2026-121637/39/40 share the same range.

## Documents

- [advisory] WatchGuard Security Advisories (PSIRT listing) https://psirt.watchguard.com/
- [fix] AuthPoint release notes (Gateway 7.6.0) https://www.watchguard.com/support/release-notes/cloud/Content/en-US/AuthPoint/EN_release-notes_authpoint.html

## From the sources

An Improper Certificate Validation vulnerability in WatchGuard AuthPoint Gateway allows an attacker with an on-path network position to intercept and modify communications between the AuthPoint Gateway and local authentication providers.

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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_