CVE-2026-13371

WatchGuard Firebox Management Web UI Denial of Service via Unsafe Deserialization

At a glance

Severity: MEDIUM 6.9
EPSS: EPSS 0.59 % · percentile 48 (2026-10-27)
State: PUBLISHED
Published: 2026-07-02
Updated: 2026-08-27
Assigner: WatchGuard
NVD status: Analyzed

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.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	MEDIUM 6.9	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	WatchGuard
CVSS 4.0	MEDIUM 6.9	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · 5d1c2695-1a31-4499-88ae-e847036fd7e3 (Secondary)
CVSS 3.1	MEDIUM 4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H	NVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

CWE-502

European references

ENISA EUVD · EUVD-2026-41447
GCVE · GCVE-0-2026-13371

Affected configurations (NVD CPE)

cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 2025.1 < 2026.2.1
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 12.5 < 12.5.19
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 12.0 < 12.12.1

Affected products

Product	Versions
WatchGuard · Fireware OS	affected 2025.1 < 2026.2.1 ; affected 12.0 < 12.12.1
WatchGuard · Fireware OS	affected 12.0 < 12.11.9
WatchGuard · Fireware OS	affected 12.0 < 12.5.19

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD