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Critical 9.1Published Oct 27, 2026

CVE-2026-103593Fireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Execution

Updated under an hour ago ()

Does this affect you?

It affects WatchGuard Fireware OS. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
9.1 CRITICAL (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H
Weakness (CWE)
CWE-121, CWE-787
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
WatchGuard
NVD analysis
Awaiting Analysis
Record last updated
Oct 28, 2026
First seen by InfoSec Signals
Oct 27, 2026

Affected products

Affected products
WatchGuard Fireware OS
watchguard:fireware_os (from the name)
from 2025.1 before 2026.4; from 12.0 before 12.12.4
CNA record

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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