CVE-2026-93857 Fireware OS Pre-Authentication Stack Buffer Overflow in SIP Proxy Allows Remote Code Execution

CriticalCVSS 9.2 EPSS 0.56%

Published: 2026-10-27 17:52
Updated: 2026-10-29 13:17
Exploit status: No public exploit known

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.

Affected products

Product	Affected versions	Fixed in
WatchGuard Fireware OS	>= 2025.1, < 2026.4	2026.4
WatchGuard Fireware OS	>= 12.0, < 12.12.4	12.12.4
WatchGuard Fireware OS	>= 12.0, < 12.5.22	12.5.22

References

psirt.watchguard.com vendor-advisory

CVSS v4.0

9.2 Critical

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable System Confidentiality: High
Vulnerable System Integrity: High
Vulnerable System Availability: High
Subsequent System Confidentiality: None
Subsequent System Integrity: None
Subsequent System Availability: None

All scores (2)

v4.0 9.2 · watchguard
v4.0 9.2 · 5d1c2695-1a31-4499-88ae-e847036fd7e3

Weakness & likelihood

EPSS (exploitation probability, 30 days): 0.56% (percentile 46.9)
CWE: CWE-120 CWE-121 CWE-787

Public exploit references

Metadata only. CVERadar never hosts or runs exploit code.

No public exploit references known.