CVE-2026-93862 PUBLISHED

Fireware OS Out-of-Bounds Read in FireCluster Sync Allows Denial of Service

Assigner: WatchGuard
Reserved: 18.09.2026 Published: 27.10.2026 Updated: 27.10.2026

An out-of-bounds read vulnerability in the FireCluster Sync processing allows an attacker positioned on the cluster interconnect, such as a compromised cluster peer or an on-path network attacker, to repeatedly crash the firewall's cluster synchronization process by sending specially crafted network traffic, resulting in a sustained denial of service.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Adjacent	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 2025.1 to 2026.4 (excl.) affected from 12.0 to 12.12.4 (excl.)

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 12.0 to 12.5.22 (excl.)

Affected Configurations

This vulnerability affects Firebox devices that are deployed in a FireCluster.

Exploits

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solutions

Fireware OS 2026.4, Fireware OS 12.12.4, Fireware OS 12.5.22

Credits

WatchGuard AI Security Research finder

References

https://psirt.watchguard.com/CVE-2026-93862

Problem Types

CWE-125 CWE
CWE-129 CWE
CWE-787 CWE
CWE-823 CWE