Integer Overflow Vulnerability in WatchGuard Fireware OS Access Portal
CVE-2026-93866

9.2CRITICAL

Key Information:

Vendor

Watchguard

Status
Fireware Os
Vendor
CVE Published:
27 October 2026

Badges

👾 Exploit Exists

What is CVE-2026-93866?

An integer overflow vulnerability exists in the WebSocket connection handling of the Access Portal feature in WatchGuard Fireware OS. This flaw enables a remote, unauthenticated attacker to potentially exploit the system by crafting a specially designed request. If successful, this could lead to writing data beyond the boundaries of a heap buffer, posing security risks to the integrity of the affected system.

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-2026-93866
vendor-advisory

CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Laurent GAFFIE , secorizon.com
.