Windows BitLocker Flaw Lets Attackers Execute Code on Vulnerable Systems

Microsoft patched CVE-2026-69449, a heap-based buffer overflow in Windows BitLocker allowing privileged local attackers to execute code; no exploitation reported.

Microsoft disclosed CVE-2026-69449 on September 8, 2026, an Important-severity heap-based buffer overflow (CWE-122) in Windows BitLocker with a CVSS 3.1 base score of 6.7. The attack vector is local (AV:L) with high privileges required, so exploitation needs privileged local access rather than remote access over the internet. Microsoft, as assigned CNA, has not reported public exploitation, and administrators are urged to inventory BitLocker-enabled systems and apply updates. Interim mitigations include least-privilege access, limiting administrative rights, and monitoring for unexpected elevated process activity.