CVE-2026-58638

Analyzed Analyzed - Analysis Complete

Windows Boot Loader Cryptographic Bypass Vulnerability

Publication date: 2026-07-14

Last updated on: 2026-07-22

Assigner: Microsoft Corporation

Description

Missing cryptographic step in Windows Boot Loader allows an authorized attacker to bypass a security feature locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-14

Last Modified

2026-07-22

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-58638

EUVD

EUVD-2026-44315

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_11_26h1	to 10.0.28000.2269 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2269 (exc)
microsoft	windows_10_1809	to 10.0.17763.9020 (exc)
microsoft	windows_10_1809	to 10.0.17763.9020 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8875 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8875 (exc)
microsoft	windows_server_2025	to 10.0.26100.33158 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8875 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8875 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7376 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7376 (exc)
microsoft	windows_server_2022	to 10.0.20348.5386 (exc)
microsoft	windows_server_2016	to 10.0.14393.9339 (exc)
microsoft	windows_server_2019	to 10.0.17763.9020 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-325	The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.

Attack-Flow Graph

Executive Summary

This vulnerability involves a missing cryptographic step in the Windows Boot Loader. An authorized attacker can exploit this to bypass a security feature locally on a system.

Impact Analysis

An attacker could bypass security protections on your system, potentially gaining unauthorized access or executing malicious actions while bypassing safeguards.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft to address the missing cryptographic step in the Windows Boot Loader.

Hi! I’m here to help you understand CVE-2026-58638. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70