Stack-Based Buffer Overflow in Fireware OS Logging Service by WatchGuard
CVE-2026-103593

9.1CRITICAL

Key Information:

Vendor

Watchguard

Status
Fireware Os
Vendor
CVE Published:
27 October 2026

Badges

👾 Exploit Exists

What is CVE-2026-103593?

The Fireware OS logging service contains a stack-based buffer overflow vulnerability that can be exploited by a network-adjacent attacker. This vulnerability occurs when an attacker manages to impersonate or intercept traffic intended for the configured log server. By presenting a specially crafted certificate, the attacker can execute arbitrary code with root privileges, posing a significant risk to network security. Organizations utilizing Fireware OS are advised to assess their exposure to this vulnerability and implement appropriate security measures.

Affected Version(s)

Fireware OS Default 2025.1 < 2026.4

Fireware OS Default 12.0 < 12.12.4

Fireware OS T15/T35 12.0 < 12.5.22

References

https://psirt.watchguard.com/CVE-2026-103593
vendor-advisory

CVSS V4

Score:
9.1
Severity:
CRITICAL
Confidentiality:
None
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

WatchGuard AI Security Research
.