widely-deployed-product-advisoryendpoint-software-vulnerabilityprivilege-escalation-technique

Microsoft Patches BitLocker and Windows Boot Manager Security Bypass Flaws

Patch & Detection Intelligence · 4 sources · Updated 4mo ago · First seen May 25, 2026

Microsoft disclosed multiple security feature bypass vulnerabilities affecting Windows BitLocker and Windows Boot Manager, publishing advisories for CVE-2025-48804, CVE-2025-48001, CVE-2025-55338, and CVE-2022-30203. The BitLocker issues were identified as bypass flaws rather than remote code execution bugs, indicating a risk that attackers could undermine disk encryption protections or related trust controls under certain conditions.

The advisories show a recurring focus on protections tied to the Windows boot chain and full-disk encryption, with three separate BitLocker bypass CVEs and one Boot Manager bypass CVE documented by Microsoft. While Microsoft did not provide public synopses in the referenced notices, the updates signal that organizations relying on BitLocker and secure startup protections should prioritize review and deployment of the relevant Windows security patches to reduce the chance of pre-boot or local protection mechanisms being circumvented.

Patch this, or something else?See real exploitation activity before you spend the cycle.

Triage this advisory

Event timeline

How this story unfolded

Events from the most recent confirmed update back to the earliest known activity.

3 events · Jul 12, 2022 – Oct 14, 2025

Oct 14, 20251y ago
Microsoft publishes advisory for CVE-2025-55338 BitLocker bypass vulnerability
Microsoft released a Security Update Guide entry for CVE-2025-55338, identified as a Windows BitLocker Security Feature Bypass Vulnerability. The reference indicates disclosure in October 2025.
Jul 8, 20251y ago
Microsoft discloses CVE-2025-48001 and CVE-2025-48804 BitLocker bypass vulnerabilities
Microsoft published Security Update Guide advisories for two Windows BitLocker Security Feature Bypass Vulnerabilities, CVE-2025-48001 and CVE-2025-48804. Both advisories were released on the same day.
Jul 12, 20224y ago
Microsoft publishes advisory for CVE-2022-30203 BitLocker-related bypass flaw
Microsoft released a Security Update Guide entry for CVE-2022-30203, described as a Windows Boot Manager Security Feature Bypass Vulnerability. This is the earliest disclosed event in the provided references.

Do you run this?See real exploitation activity behind this advisory so you can triage it against everything else in the queue.

Prioritize This Patch

Source coverage

Sources

4 references tracked. Mallory keeps watching after this page renders.

Msrc MicrosoftAdvisories · Oct 14, 2025

CVE-2025-55338 - Security Update Guide - Microsoft - Windows BitLocker Security Feature Bypass VulnerabilityOpen source ↗

Msrc Product AdvisoriesAdvisories · Jul 8, 2025

CVE-2025-48804 - Security Update Guide - Microsoft - Windows BitLocker Security Feature Bypass VulnerabilityOpen source ↗

Msrc Product AdvisoriesAdvisories · Jul 8, 2025

CVE-2025-48001 - Security Update Guide - Microsoft - Windows BitLocker Security Feature Bypass VulnerabilityOpen source ↗

Msrc Product AdvisoriesAdvisories · Jul 12, 2022

CVE-2022-30203 - Security Update Guide - Microsoft - Windows Boot Manager Security Feature Bypass VulnerabilityOpen source ↗

Mallory platform

See the full picture, correlated to your attack surface.

This page covers what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which threat actors are using it right now, and what to deploy next.

Start Free Trial Open in App

Exposure mappingMap indicators from this story to your assets and identify affected systems in minutes.

Threat actor evidenceEvery observed campaign, victim, and pivot linked to actors named in this story.

Associated malwareMalware, exploits, and IOCs connected to the activity described here.

Detection signaturesYARA, Sigma, and Snort rules deployed to your SIEM as soon as they’re published.

Scheduled alertsGet matching new stories delivered to your team as they break, not the next morning.

AI threadsAsk questions about this story and take action on the answers.

Microsoft Patches BitLocker and Windows Boot Manager Security Bypass Flaws

How this story unfolded

Microsoft publishes advisory for CVE-2025-55338 BitLocker bypass vulnerability

Microsoft discloses CVE-2025-48001 and CVE-2025-48804 BitLocker bypass vulnerabilities

Microsoft publishes advisory for CVE-2022-30203 BitLocker-related bypass flaw

Sources

See the full picture, correlated to your attack surface.

Related stories

Microsoft Flags Windows Security Feature Bypass Vulnerabilities

Windows BitLocker Physical Attack Bypass Exposes Encrypted Devices

Microsoft Fixes BitLocker Bypass and Other Zero-Days in June Security Updates

Microsoft Patches BitLocker and Windows Boot Manager Security Bypass Flaws

How this story unfolded

Microsoft publishes advisory for CVE-2025-55338 BitLocker bypass vulnerability

Microsoft discloses CVE-2025-48001 and CVE-2025-48804 BitLocker bypass vulnerabilities

Microsoft publishes advisory for CVE-2022-30203 BitLocker-related bypass flaw

Sources

See the full picture, correlated to your attack surface.

Related stories

Microsoft Flags Windows Security Feature Bypass Vulnerabilities

Windows BitLocker Physical Attack Bypass Exposes Encrypted Devices

Microsoft Fixes BitLocker Bypass and Other Zero-Days in June Security Updates