CVE-2026-58638

MEDIUM

Published Jul 14, 2026 Modified Jul 17, 2026 CWE-325

Description

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

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CVSS v3.1 Score

6.0

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0023

Probability of exploitation

0.14%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-325 CWE-325

Affected Products

Vendor	Product	Versions
microsoft	windows_10_1809	< 10.0.17763.9020
microsoft	windows_10_1809	< 10.0.17763.9020
microsoft	windows_10_21h2	< 10.0.19044.7548
microsoft	windows_10_21h2	< 10.0.19044.7548
microsoft	windows_10_21h2	< 10.0.19044.7548
microsoft	windows_10_22h2	< 10.0.19045.7548
microsoft	windows_10_22h2	< 10.0.19045.7548
microsoft	windows_10_22h2	< 10.0.19045.7548
microsoft	windows_11_23h2	< 10.0.22631.7376
microsoft	windows_11_23h2	< 10.0.22631.7376
microsoft	windows_11_24h2	< 10.0.26100.8875
microsoft	windows_11_24h2	< 10.0.26100.8875
microsoft	windows_11_25h2	< 10.0.26200.8875
microsoft	windows_11_25h2	< 10.0.26200.8875
microsoft	windows_11_26h1	< 10.0.28000.2269
microsoft	windows_11_26h1	< 10.0.28000.2269
microsoft	windows_server_2012	All
microsoft	windows_server_2012	All
microsoft	windows_server_2016	< 10.0.14393.9339
microsoft	windows_server_2019	< 10.0.17763.9020
microsoft	windows_server_2022	< 10.0.20348.5386
microsoft	windows_server_2025	< 10.0.26100.33158

References

Advisories & Patches

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58638

Frequently Asked Questions

What is CVE-2026-58638? +

Missing cryptographic step in Windows Boot Loader allows an authorized attacker to bypass a security feature locally. It has a CVSS v3.1 base score of 6.0 (MEDIUM).

How severe is CVE-2026-58638? +

CVE-2026-58638 has a CVSS v3.1 score of 6.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0023, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-58638? +

CVE-2026-58638 affects products from microsoft, specifically: windows_10_1809, windows_10_21h2, windows_10_22h2, windows_11_23h2, windows_11_24h2, windows_11_25h2, windows_11_26h1, windows_server_2012, windows_server_2016, windows_server_2019, windows_server_2022, windows_server_2025. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-58638? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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