Medium 6.9Published Jul 2, 2026

CVE-2026-13371WatchGuard Firebox Management Web UI Denial of Service via Unsafe Deserialization

Updated under an hour ago (Oct 28, 2026, 12:20 AM ET)

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It affects WatchGuard Fireware OS and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

An authenticated administrator can trigger a denial-of-service condition in the Fireware Management Web UI by sending malformed or crafted data to the put_data endpoint, which performs unsafe deserialization of the attacker-supplied input.

CVSS: 6.9 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness (CWE): CWE-502
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: Analyzed
Record last updated: Aug 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

WatchGuard Fireware OS watchguard:fireware_os (from the name)	from 2025.1 before 2026.2.1; from 12.0 before 12.12.1	CNA record
watchguard fireware watchguard:fireware	from 2025.1 before 2026.2.1; from 12.5 before 12.5.19; from 12.0 before 12.12.1	NVD

References

References

https://psirt.watchguard.com/CVE-2026-13371	vendor-advisory, broken-link
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00014	vendor-advisory

The CVE record on cve.org NVD's entry

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.