CVE-2026-58638

MEDIUMNVD 5.56.0▲
EchelonGraph scoreHIGH confidence

Score 6.0 from GitHub Security Advisory published 2026-07-14. NVD baseline CVSS 5.5; sources differ by 0.5.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 5 sources updated this week
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
5.5
EG Score
6.0(high)
EG Risk
—
EPSS
13.8%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 22, 2026

Advisory Details (1)

Auto-updated Jul 15, 2026
Patch available. Sources: microsoft.
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

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

Vendor Advisories for CVE-2026-58638(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-20 17:08 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 02:41 UTCEG score recompute
  9. 2026-07-19 02:41 UTCVendor advisory
  10. 2026-07-19 02:41 UTCGHSA enrichment
  11. 2026-07-19 02:29 UTCEPSS rescore
  12. 2026-07-18 10:04 UTCEPSS rescore
  13. 2026-07-17 07:19 UTCEG score recompute
  14. 2026-07-17 07:19 UTCVendor advisory
  15. 2026-07-17 07:19 UTCGHSA enrichment
  16. 2026-07-17 03:24 UTCNVD updateCVSS v3 → 5.5
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-16 16:53 UTCVendor advisory
  19. 2026-07-16 16:53 UTCGHSA enrichment
  20. 2026-07-15 17:06 UTCVendor advisory
  21. 2026-07-15 17:06 UTCGHSA enrichment
  22. 2026-07-15 16:57 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-14 17:40 UTCMITRE cvelistV5first tracked
  25. 2026-07-14 17:40 UTCEG score recompute
Show 1 more
  1. 2026-07-14 17:40 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-58638?
CVE-2026-58638 is a medium vulnerability published on July 14, 2026. Missing cryptographic step in Windows Boot Loader allows an authorized attacker to bypass a security feature locally.
When was CVE-2026-58638 disclosed?
CVE-2026-58638 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-58638 actively exploited?
CVE-2026-58638 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-58638?
CVE-2026-58638 has a CVSS v3 base score of 5.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.0.
How do I remediate CVE-2026-58638?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58638, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-58638

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