by Kastro
Paper/Archive/CVE-2026-93857

CVE-2026-93857

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

EPSS 0.5%CVSS 9.2
critical.is priorityof 100
36
CVSS 9.2 (CNA)9.2 / 10 × 3027.6Not in CISA KEV+300.0EPSS percentile 40.7.407 × 208.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
Fireware OS2025.1 – < 2026.42026.4CNA
Fireware OS12.0 – < 12.12.412.12.4CNA
Fireware OS12.0 – < 12.5.2212.5.22CNA

Scores by source

WatchGuard (CNA)9.2CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorypsirt.watchguard.com/CVE-2026-93857