All vulnerabilities
CVE-2026-86128

Fireware OS NULL Pointer Dereference in NetFlow IPv6 Traffic Processing Allows Remote Denial of Service

WatchGuard Fireware OSNetwork & edge
Open in ThreatlineRecord JSON
CVSS
8.2High
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

A NULL pointer dereference vulnerability in Fireware OS's NetFlow packet-processing feature allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted IPv6 packet.

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