SB2026071534 - Multiple vulnerabilities in Microsoft Windows Web Proxy Auto-Discovery Protocol (WPAD)

Description

This security bulletin contains information about 2 vulnerabilities.

1) Integer overflow (CVE-ID: CVE-2026-49800)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to integer overflow in Windows Web Proxy Auto-Discovery Protocol (WPAD). A local user can pass specially crafted data to the application, trigger integer overflow and gain elevated privileges on the system.

2) Heap-based buffer overflow (CVE-ID: CVE-2026-50480)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to a boundary error in Windows Web Proxy Auto-Discovery Protocol (WPAD). A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-49800
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50480