All vulnerabilities
CVE-2026-93857

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

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

A stack-based buffer overflow vulnerability in Fireware OS's SIP proxy allows a remote, unauthenticated attacker to execute arbitrary code by sending a specially crafted request through a policy that uses the SIP proxy.

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