CVE-2026-20864
Published: 13 January 2026
Summary
CVE-2026-20864 is a high-severity Heap-based Buffer Overflow (CWE-122) 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 9.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-20864 is a heap-based buffer overflow vulnerability (CWE-122) in the Connected Devices Platform Service (Cdpsvc) on Windows systems. Published on 2026-01-13, it has 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), rated as high severity. The flaw resides in Cdpsvc, a service handling connected devices functionality, enabling local privilege escalation for authorized attackers with low-privilege access.
An attacker with local access and low privileges (PR:L) can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation allows arbitrary code execution with elevated privileges, potentially granting high-impact confidentiality, integrity, and availability compromises (C:H/I:H/A:H) within the affected system's scope.
The Microsoft Security Response Center (MSRC) advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20864 provides details on mitigation, including available patches and recommended actions for affected Windows versions. Security practitioners should review the advisory for specific update guidance and apply patches promptly to prevent exploitation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2164
Vulnerability details
Heap-based buffer overflow in Connected Devices Platform Service (Cdpsvc) allows an authorized attacker to elevate privileges locally.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Heap buffer overflow in Windows service directly enables local arbitrary code execution for privilege escalation (T1068).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely identification, reporting, and correction of flaws like the heap-based buffer overflow in Cdpsvc through vendor patches as advised by MSRC.
Implements memory protections such as ASLR, DEP, and heap hardening that directly mitigate exploitation of heap-based buffer overflows in services like Cdpsvc.
Enforces least privilege on processes and services, limiting the impact of local privilege escalation from low-privilege attackers exploiting Cdpsvc.