CVE-2026-4266An 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 i…
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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
- 6.7 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- 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
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Aug 28, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
watchguard fireware watchguard:fireware | from 2025.1 before 2026.2; from 12.1 before 12.12 | NVD |
References
- https://psirt.watchguard.com/CVE-2026-4266broken-link
- https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00007vendor-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.