Vulnerability · Published Jul 2, 2026 · Assigned by WatchGuard
CVE-2026-13371WatchGuard Firebox Management Web UI Denial of Service via Unsafe Deserialization
Medium 6.9
In plain English
A medium-severity unsafe deserialization in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.6%top 51.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WatchGuard | Fireware OS | 2025.1 – before 2026.2.112.0 – before 12.12.1 |
| WatchGuard | Fireware OS | 12.0 – before 12.11.9 |
| WatchGuard | Fireware OS | 12.0 – before 12.5.19 |
Weakness: CWE-502 · Vector: 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
References
- https://psirt.watchguard.com/CVE-2026-13371 vendor-advisory
- https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00014 vendor-advisory