CVE-2026-4266
WatchGuard Firebox Insecure Deserialization in Fireware Access Portal
HIGH 8.4
At a glance
- Source
- NVD
- EPSS
- EPSS 0.27 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- WatchGuard
- NVD status
- Analyzed
Description
An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.
Weaknesses (CWE)
- CWE-502 — Deserialization of Untrusted Data
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 8.4 | CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | WatchGuard |
| CVSS 4.0 | HIGH 8.4 | CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/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 6.7 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-17079
- GCVE · GCVE-0-2026-4266
Affected configurations (NVD CPE)
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*≥ 2025.1 < 2026.2cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*≥ 12.1 < 12.12
Affected products
| Product | Versions |
|---|---|
| WatchGuard · Fireware OS | affected 2025.1 < 2026.2 ; affected 12.1 < 12.12 |
| WatchGuard · Fireware OS | affected 12.1 < 12.11.9 |
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 |