CVE-2026-20810

Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Scoring

Severity

HIGH

CVSS base score

7.8

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

EPSS probability

0.49%

CWE

CWE-590

Published

2026-01-13

Last modified

2026-07-30

Affected products

• Microsoft Windows 10 Version 1809
• Microsoft Windows 10 Version 21H2
• Microsoft Windows 10 Version 22H2
• Microsoft Windows Server 2019
• Microsoft Windows Server 2019 (Server Core installation)

Weakness type

• CWE-590

Related vulnerabilities

• CVE-2026-89161 — In PCRE2 before 10.48, pcre2_jit_match mishandles a previously copied subject being passed in as a...
• CVE-2026-18582 — mz-automation libiec61850 Report Sending Path reporting.c Reporting_RCBWriteAccessHandler free of memory not on the heap
• CVE-2025-7006 — Avast antivirus use of stack memory after free when scanning a malformed PE file
• CVE-2026-47328 — Invalid pointer deallocation in Ubuntu Linux AppArmor notification handling
• CVE-2025-54899 — Microsoft Excel Remote Code Execution Vulnerability
• CVE-2025-42996 — Multiple vulnerabilities in SAP MDM Server
• CVE-2025-42995 — Multiple vulnerabilities in SAP MDM Server
• CVE-2025-42994 — Multiple vulnerabilities in SAP MDM Server

Markdown version · Browse all CVEs