CVE-2026-25166
Published: 10 March 2026
Summary
CVE-2026-25166 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 22.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-25166 is a deserialization of untrusted data vulnerability (CWE-502) in Windows System Image Manager. The flaw carries a CVSS 3.1 score of 7.8 and permits an attacker to execute arbitrary code on an affected Windows system when maliciously crafted input is processed.
An authorized local attacker with low privileges can exploit the issue without user interaction. Successful exploitation grants full control over confidentiality, integrity, and availability on the target host, enabling the attacker to run code, access sensitive data, or install additional payloads.
The sole reference points to the Microsoft Security Response Center advisory, which security teams should consult for official patch availability and mitigation guidance.
The associated EPSS score sits at a low 0.0106 with no material increase from its recorded peak, indicating limited observed exploitation interest following disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10629
Vulnerability details
Deserialization of untrusted data in Windows System Image Manager allows an authorized attacker to execute code locally.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local deserialization vulnerability (CWE-502) in a Windows utility directly enables arbitrary code execution by a low-privileged local attacker (AV:L/PR:L/UI:N), mapping to exploitation for privilege escalation or code execution within the local context.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Timely flaw remediation through applying Microsoft patches directly eliminates the deserialization vulnerability in Windows System Image Manager.
Information input validation ensures untrusted data deserialized by Windows System Image Manager is checked for validity, preventing exploitation leading to code execution.
Memory protection safeguards mitigate arbitrary code execution resulting from successful deserialization attacks in Windows System Image Manager.