# CVE-2026-121639 — WatchGuard AuthPoint Authentication Gateway

> As of 2026-11-06, CVE-2026-121639 is a Critical-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in WatchGuard AuthPoint Authentication Gateway, CVSS v4.0 9.2, EPSS 0.6% (52.1th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-121639, most recently “Multi-vendor vulnerability roundup: Node2Shell Brotli RCE (CVE-2026-111497, actively exploited, CISA KEV), WatchGuard CVE-2026-98432 (CVSS 9.8) and AuthPoint Gateway flaws, Cisco UCS Central CVE-2026-76506, SonicWall GMS CVE-2026-109593/109594 unpatched (EOL)”.

**Last updated:** 2026-11-04

## What is CVE-2026-121639?

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.

The record classifies CVE-2026-121639 under weakness classes [CWE-252](https://cwe.mitre.org/data/definitions/252.html), [CWE-287](https://intel.threadlinqs.com/cwe/CWE-287), [CWE-306](https://intel.threadlinqs.com/cwe/CWE-306). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 2 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 9.2 — Critical (derived from score) (`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`)
- **EPSS (FIRST):** 0.6% probability of exploitation in the next 30 days, higher than 52.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-11-04

## Is CVE-2026-121639 being exploited?

It currently carries a trending score of 48 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [WatchGuard](https://intel.threadlinqs.com/vendors/watchguard): AuthPoint Authentication Gateway

## How to fix CVE-2026-121639

Vendor advisory: [https://psirt.watchguard.com/CVE-2026-121639](https://psirt.watchguard.com/CVE-2026-121639). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-121639

1 tracked threat in the Threadlinqs corpus references CVE-2026-121639, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multi-vendor vulnerability roundup: Node2Shell Brotli RCE (CVE-2026-111497, actively exploited, CISA KEV), WatchGuard CVE-2026-98432 (CVSS 9.8) and AuthPoint Gateway flaws, Cisco UCS Central CVE-2026-76506, SonicWall GMS CVE-2026-109593/109594 unpatched (EOL)](https://intel.threadlinqs.com/threat/TL-2026-5372) — CRITICAL · 2026-11-06

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-11-06. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [psirt.watchguard.com — vendor advisory](https://psirt.watchguard.com/CVE-2026-121639)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-121639
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