# CVE-2026-121638: WatchGuard AuthPoint Gateway improper certificate validation

Source: https://junglewise.ai/threats/cve-2026-121638-an-improper-certificate-validation-vulnerability-in-watchguard  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-121638 · Severity: info · Published 2026-11-04

WatchGuard AuthPoint Gateway is an authentication service that validates user identities and communicates with corporate directory systems. An improper certificate validation flaw allows a network attacker positioned between the gateway and authentication servers to intercept and alter login credentials or authentication requests, potentially gaining unauthorized access to systems protected by the gateway.

Technologies: [Watchguard AuthPoint Authentication Gateway](https://junglewise.ai/threats/technologies/authpoint-authentication-gateway). Vendors: [Watchguard](https://junglewise.ai/threats/vendors/watchguard).

## Quick answers

**Is CVE-2026-121638 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121638 being exploited in the wild.

**How severe is CVE-2026-121638?** Informational severity, published 4 November 2026.

**Which products and versions are affected?** Watchguard AuthPoint Authentication Gateway < 7.6.0.

**Is there a fix for CVE-2026-121638?** Yes: fixed in AuthPoint Authentication Gateway 7.6.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-121638 attacked?** It is attacked over the network or from the adjacent network, in a hosted service.

**Am I affected by CVE-2026-121638?** Check whether you run Watchguard AuthPoint Authentication Gateway at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in AuthPoint Authentication Gateway 7.6.0

## Technical details

The vulnerability stems from improper certificate validation (CWE-295) in the AuthPoint Gateway's communication with RADIUS, LDAP, or ADFS authentication providers. An attacker with an on-path network position can perform a man-in-the-middle attack to intercept and modify communications. The vulnerability affects versions before 7.6.0 only when the gateway is configured to use one of these authentication resources.

## Affected products

- WatchGuard AuthPoint Authentication Gateway < 7.6.0

## Timeline

- 2026-11-04: disclosed
- 2026-11-04: advisory

## References

- [https://psirt.watchguard.com/CVE-2026-121638](https://psirt.watchguard.com/CVE-2026-121638)

## Related threats

- [WatchGuard AuthPoint Gateway authentication bypass by capture-replay](https://junglewise.ai/threats/cve-2026-121640-an-authentication-bypass-by-capture-replay-vulnerability-in)
- [WatchGuard AuthPoint Gateway authentication bypass](https://junglewise.ai/threats/cve-2026-121639-a-missing-authentication-for-critical-function-vulnerability-in)
- [WatchGuard AuthPoint Gateway improper HMAC validation in LDAP authentication](https://junglewise.ai/threats/cve-2026-121637-an-improper-integrity-validation-vulnerability-in-watchguard)
- [WatchGuard AuthPoint Gateway authentication bypass in LDAP Sync](https://junglewise.ai/threats/cve-2026-95676-a-missing-improper-authentication-vulnerability-in-the-watchguard)