CVE-2026-20810
Microsoft Windows 10 1809 ≤ 10.0.17763.8276
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-20810 is a high-severity Free of Memory not on the Heap (CWE-590) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-20810 is a vulnerability in the Windows Ancillary Function Driver for WinSock involving a free of memory not on the heap, classified under CWE-590. Published on 2026-01-13, it carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and affects Windows systems utilizing this driver.
A local attacker with low privileges can exploit the vulnerability due to its low attack complexity and lack of required user interaction. Successful exploitation enables privilege escalation, resulting in high impacts to confidentiality, integrity, and availability.
Microsoft's update guide provides details on mitigation and patches at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20810.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2194
Vulnerability Data
Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static/dynamic analysis) can discover incorrect free() calls on non-heap memory.
Documented development standards and tools can require correct heap allocation/deallocation discipline, stopping the defect at introduction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent incorrect free() calls via code review, static analysis, and developer training.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect invalid-free defects before release.
Secure development lifecycle mandates memory-safety practices that reduce use-after-free and invalid-free bugs.
Secure architecture and engineering principles include disciplined memory management that prevents freeing non-heap memory.
Secure coding standards explicitly forbid freeing pointers not obtained from heap allocators, directly mitigating CWE-590.