CVE-2026-4266

mediumpriority · track · 27EPSS 0.003 · 20 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.27% (20th) EPSS

CVSS 6.7 · medium

Is it mine?

11 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.7–8.4

v3.16.7mediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 0.8 · impact 5.9

v4.08.4highCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:Nsecondary · ENISA EU

v4.08.4highCVSS: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:Xsecondary

v4.05.7mediumCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-502US

affected products (11)

Products and version ranges known to be affected.

WatchGuard Firebox 11.xall versionscert_bundDEcpe:/a:watchguard:firebox:11.x
WatchGuard Firebox <12.12all versionscert_bundDE
WatchGuard Firebox <12.5.18all versionscert_bundDE
WatchGuard Firebox <2026.2all versionscert_bundDE
WatchGuard Firebox< 12.12cert_bundDE
WatchGuard Firebox< 12.5.18cert_bundDE
WatchGuard Firebox< 2026.2cert_bundDE
WatchGuard Fireware OS12.1 → 12.12enisa_euvdEU
WatchGuard Fireware OS2025.1 → 2026.2enisa_euvdEU
watchguard fireware12.1 → 12.12nvdUScpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*
watchguard fireware2025.1 → 2026.2nvdUScpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-0892WatchGuard Firebox: Mehrere SchwachstellenDeutsch2026-03-26csaf · cert_bundDE
Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in WatchGuard Firebox ausnutzen, um beliebigen Programmcode auszuführen oder einen Denial of Service zu verursachen.

also known as (2)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund nvd NVD CVE.org MITRE

published 2026-03-30modified 2026-08-28

references (6)

External citations — patches, advisories, analysis.

scry

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