SB2026061148 - Multiple vulnerabilities in Microsoft Windows TCP/IP

Description

This security bulletin contains information about 2 vulnerabilities.

1) Heap-based buffer overflow (CVE-ID: CVE-2026-42904)

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

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

The vulnerability allows a remote attacker to escalate privileges on the target system.

The vulnerability exists due to a boundary error in Windows TCP/IP. A remote attacker on the local network can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the target system.

2) Incorrect Calculation of Buffer Size (CVE-ID: CVE-2026-42915)

CWE-ID: CWE-131 - Incorrect Calculation of Buffer Size

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

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in Windows TCP/IP. A remote user on the local network can trigger memory corruption and cause a denial of service condition on the target system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42904
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42915