CVE-2026-50480: Windows Web Proxy Auto-Discovery Protocol (WPAD) Elevation of Privilege Vulnerability

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-14 · updated 2026-10-28
Weakness: CWE-122

Description

Heap-based buffer overflow in Windows Web Proxy Auto-Discovery Protocol (WPAD) allows an authorized attacker to elevate privileges locally.

Affected products

Microsoft Windows 10 1607: before 10.0.14393.9339 — fixed in 10.0.14393.9339
Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: before 10.0.14393.9339 — fixed in 10.0.14393.9339
Microsoft Windows 10 1607: from 10.0.14393.0 before 10.0.14393.9339 — fixed in 10.0.14393.9339
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.26226 — fixed in 6.2.9200.26226
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.23291 — fixed in 6.3.9600.23291
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.9339 — fixed in 10.0.14393.9339

How to fix

Upgrade to a fixed version: Microsoft Windows 10 1607 10.0.14393.9339; Microsoft Windows Server 2016 10.0.14393.9339; Microsoft Windows 10 1607 10.0.14393.9339; Microsoft Windows Server 2012 6.2.9200.26226; Microsoft Windows Server 2012 R2 6.3.9600.23291; Microsoft Windows Server 2016 10.0.14393.9339. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50480

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