CVE-2026-27913
Published: 14 April 2026
Summary
CVE-2026-27913 is a high-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Windows Server 2012. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 30.0th 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-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-27913 is an improper input validation vulnerability (CWE-20) affecting Windows BitLocker. Published on 2026-04-14, it enables an unauthorized attacker to bypass a security feature locally on impacted systems. The vulnerability carries a CVSS v3.1 base score of 7.7 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N), indicating high severity due to its potential for significant confidentiality and integrity impacts.
A local attacker can exploit this issue with low attack complexity, requiring no privileges, user interaction, or special conditions. Exploitation allows bypassing BitLocker's security protections, potentially granting unauthorized access to encrypted data or altering protected resources without affecting availability.
Microsoft's update guide provides details on mitigation, available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-27913. Security practitioners should consult this advisory for patching instructions and workarounds.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-22455
Vulnerability details
Improper input validation in Windows BitLocker allows an unauthorized attacker to bypass a security feature locally.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Bypassing BitLocker via local input validation flaw directly enables reading encrypted local files/data (T1005) and modifying protected on-disk resources (T1565.001).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly addresses the improper input validation (CWE-20) flaw in Windows BitLocker that enables local bypass of security features.
Ensures timely patching and remediation of the BitLocker vulnerability as detailed in Microsoft's update guide, eliminating the exploit path.
Vulnerability scanning identifies systems affected by CVE-2026-27913 for prioritized patching and mitigation.