SB20260512129 - Multiple vulnerabilities in Microsoft Windows TCP/IP

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Main Vulnerability Database SB20260512129

SB20260512129 - Multiple vulnerabilities in Microsoft Windows TCP/IP

Published: May 12, 2026

Security Bulletin ID SB20260512129
CSH Severity
High
Patch available
YES
Number of vulnerabilities 10
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 10% Medium 40% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 10 vulnerabilities.


1) Race condition (CVE-ID: CVE-2026-34334)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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 system.

The vulnerability exists due to a race condition in Windows TCP/IP. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.


2) Use-after-free (CVE-ID: CVE-2026-40415)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Windows TCP/IP. A remote attacker can execute arbitrary code on the target system.


3) Race condition (CVE-ID: CVE-2026-34351)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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 system.

The vulnerability exists due to a race condition in Windows TCP/IP. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.


4) NULL pointer dereference (CVE-ID: CVE-2026-40414)

CWE-ID: CWE-476 - NULL Pointer Dereference

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


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

The vulnerability exists due to a NULL pointer dereference error in Windows TCP/IP. A remote attacker on the local network can pass specially crafted data to the application and perform a denial of service (DoS) attack.


5) Stack-based buffer overflow (CVE-ID: CVE-2026-40399)

CWE-ID: CWE-121 - Stack-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 TCP/IP. A local user can trigger stack-based buffer overflow and gain elevated privileges on the target system.


6) NULL pointer dereference (CVE-ID: CVE-2026-40405)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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 NULL pointer dereference error in Windows TCP/IP. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.


7) Use-after-free (CVE-ID: CVE-2026-40406)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Windows TCP/IP. A remote attacker can gain access to sensitive information on the system.


8) NULL pointer dereference (CVE-ID: CVE-2026-40401)

CWE-ID: CWE-476 - NULL Pointer Dereference

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


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

The vulnerability exists due to a NULL pointer dereference error in Windows TCP/IP. A local attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.


9) NULL pointer dereference (CVE-ID: CVE-2026-40413)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/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 NULL pointer dereference error in Windows TCP/IP. A remote attacker on the local network can pass specially crafted data to the application and perform a denial of service (DoS) attack.


10) Heap-based buffer overflow (CVE-ID: CVE-2026-33837)

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 TCP/IP. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the target system.


Remediation

Install update from vendor's website.

References