A Decade of BitLocker Vulnerabilities: What’s Patched, What’s Not, and What Still Works💬

A few days ago we wrote about YellowKey, the newest entry in what has become a remarkably long list of BitLocker bypasses. That article walked through one specific attack with a practical workflow. This follow-up steps back and surveys the broader landscape: where BitLocker has been broken before, where it is still broken today, and what an investigator should expect to encounter on a seized Windows machine in 2026.

We tried to keep it deliberately high-level. For a much deeper rabbit hole, the single best starting point is Rairii’s curated catalogue at github.com/Wack0/bitlocker-attacks, which tracks the boot-manager bug pipeline more thoroughly than any vendor write-up.

The newest entry in this catalogue, and the reason we are writing the overview, is YellowKey. It belongs in the software and boot-chain family alongside bitpixie and BitUnlocker: pure software, no special hardware, and TPM-agnostic – the bug sits inside the Windows Recovery Environment rather than in the boot manager or the TPM stack, so dTPM, fTPM, and Pluton platforms are equally exposed because none of them are in the loop🔥

The operational bar is unusually low even by the standards of that family. In our view that makes YellowKey the most accessible currently-active BitLocker bypass on the public record. The structural mitigation, Microsoft’s Trusted WIM Boot – which hashes WinRE.wim against a known-trusted value and refuses to auto-unlock the OS volume on mismatch – is enforced on some recent OEM images but is not the default across most of the fielded install base, which is why YellowKey fails on a some laptops and works on the others. Notably, as the attack lives inside WinRE rather than requiring a downgrade to an older signed bootloader, the eventual PCA 2011 DBX enforcement we discuss below will not retire YellowKey – only broader Trusted WIM Boot rollout will.

More in our new article📎