All vulnerabilities
CVE-2026-81433

Fireware OS Pre-Authentication Stack Buffer Overflow in fingerd Allows Remote Code Execution

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)0.20%Chance of exploitation activity in the next 30 days, higher than 9% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in2026.3.2Also 2026.2.3, 12.12.3CVE List
Published29 Sep 2026Updated 1 Oct 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

A stack-based buffer overflow vulnerability in WatchGuard Fireware OS's DHCP fingerprinting daemon (fingerd) allows an unauthenticated attacker with adjacent network access to execute arbitrary code or crash the process by sending a specially crafted DHCP packet.

Text from CVE List

Affected versions 3

  • 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

References 1