All vulnerabilities
CVE-2026-86104

Fireware OS Resource Exhaustion in Login Process Allows Denial of Service

WatchGuard Fireware OSNetwork & edge
Open in ThreatlineRecord JSON
CVSS
8.7High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in2026.3.2Also 2026.2.3, 12.12.3 and 1 moreCVE List
Published29 Sep 2026Updated 30 Sep 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

An uncontrolled resource consumption vulnerability in the Fireware OS login process (wgagent) allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted request.

Text from CVE List

Affected versions 4

  • Fireware OSaffected: 2026.3 before 2026.3.2CVE List
  • Fireware OSaffected: 2025.0 before 2026.2.3CVE List
  • Fireware OSaffected: 12.0 before 12.12.3CVE List
  • Fireware OSaffected: 12.0 before 12.5.21CVE List

References 1