Windows BitLocker Secure Boot Security Feature Bypass
CVE-2026-27913 is an Important security feature bypass vulnerability in Windows BitLocker caused by improper input validation. According to the provided content and Microsoft advisory summary, BitLocker improperly validates certain input data, allowing an unauthorized attacker with local access to bypass a security feature. The primary documented consequence is bypass of Secure Boot, the UEFI trust mechanism intended to ensure that only trusted and properly signed software executes during system startup. The issue affects Windows Server 2012, 2012 R2, 2016, 2019, and 2022, including both full desktop and Server Core installations.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Windows BitLocker security feature bypass vulnerability caused by improper input validation that allows a local unauthorized attacker to bypass Secure Boot and undermine device confidentiality and integrity.
A Windows BitLocker security feature bypass vulnerability caused by improper input validation.
A Windows BitLocker security feature bypass vulnerability.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.