CVE-2026-4266

Summary

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.

Affected Software

VendorProductVersion RangeStatus
WatchGuardFireware OS2025.1 < 2026.2affected
WatchGuardFireware OS12.1 < 12.12affected

Weaknesses

  • CWE-502: CWE-502

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References