by Kastro
Paper/Archive/CVE-2026-103593

CVE-2026-103593

WatchGuard Fireware OS — Fireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Execution

EPSS 0.1%CVSS 9.1
critical.is priorityof 100
28
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 0.8.008 × 200.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

A stack-based buffer overflow vulnerability in the Fireware OS logging service allows a network-adjacent attacker who can impersonate or intercept traffic to the configured log server to execute arbitrary code with root privileges by presenting a specially crafted certificate.

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)9.1CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

advisorypsirt.watchguard.com/CVE-2026-103593