All vulnerabilities
CVE-2026-93866

Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Write

WatchGuard Fireware OSNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.2Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in2026.4Also 12.12.4, 12.5.22CVE List
Published27 Oct 2026Updated 27 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

An integer overflow vulnerability in the WebSocket connection handling used by WatchGuard Fireware OS's Access Portal allows a remote, unauthenticated attacker to write beyond the bounds of a heap buffer by sending a specially crafted request while the Access Portal feature is enabled.

Text from CVE List

Affected versions 3

  • Fireware OSaffected: 2025.1 before 2026.4CVE List
  • Fireware OSaffected: 12.0 before 12.12.4CVE List
  • Fireware OSaffected: 12.0 before 12.5.22CVE List

References 1