CVE-2026-93857

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

At a glance

Severity: CRITICAL 9.2
State: PUBLISHED
Published: 2026-10-27
Updated: 2026-10-27
Assigner: WatchGuard
NVD status: Received

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.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	CRITICAL 9.2	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	WatchGuard
CVSS 4.0	CRITICAL 9.2	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · 5d1c2695-1a31-4499-88ae-e847036fd7e3 (Secondary)

Weaknesses (CWE)

European references

ENISA EUVD · EUVD-2026-111156
GCVE · GCVE-0-2026-93857

Affected products

Product	Versions
WatchGuard · Fireware OS	affected 2025.1 < 2026.4 ; affected 12.0 < 12.12.4
WatchGuard · Fireware OS	affected 12.0 < 12.5.22

References

https://psirt.watchguard.com/CVE-2026-93857

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD