CVE-2026-54121

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-14. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this weekElevated
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

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

Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.

CVSS v3
8.8
EG Score
8.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
60.8%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 24, 2026

Advisory Details (1)

Auto-updated Jul 14, 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-2026-54121

Vendor Advisories for CVE-2026-54121(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 13× in last 7d / 29× 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. 2026-07-25 14:18 UTCEPSS rescore
  2. 2026-07-24 14:18 UTCEPSS rescore
  3. 2026-07-23 14:18 UTCEPSS rescore
  4. 2026-07-23 03:19 UTCEG score recompute
  5. 2026-07-22 14:08 UTCEPSS rescore
  6. 2026-07-21 15:25 UTCEPSS rescore
  7. 2026-07-20 17:08 UTCEPSS rescore
  8. 2026-07-19 14:31 UTCEPSS rescore
  9. 2026-07-19 14:31 UTCEPSS rescore
  10. 2026-07-19 02:59 UTCEG score recompute
  11. 2026-07-19 02:59 UTCVendor advisory
  12. 2026-07-19 02:59 UTCGHSA enrichment
  13. 2026-07-19 02:29 UTCEPSS rescore
  14. 2026-07-18 10:04 UTCEPSS rescore
  15. 2026-07-17 01:07 UTCVendor advisory
  16. 2026-07-17 01:07 UTCGHSA enrichment
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-16 14:03 UTCGHSA enrichment
  19. 2026-07-16 02:59 UTCVendor advisory
  20. 2026-07-16 02:59 UTCGHSA enrichment
  21. 2026-07-15 16:57 UTCEPSS rescore
  22. 2026-07-15 16:57 UTCEPSS rescore
  23. 2026-07-15 15:54 UTCVendor advisory
  24. 2026-07-15 15:54 UTCGHSA enrichment
  25. 2026-07-15 04:50 UTCVendor advisory
Show 4 more
  1. 2026-07-15 04:50 UTCGHSA enrichment
  2. 2026-07-14 17:45 UTCEG score recompute
  3. 2026-07-14 17:45 UTCVendor advisory
  4. 2026-07-14 17:40 UTCMITRE cvelistV5first tracked

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCaniqfakhrul/CVE-2026-54121
    First seen Jul 23, 2026

    Certighost POC

    Open source ↗

Frequently asked(5)

What is CVE-2026-54121?
CVE-2026-54121 is a high vulnerability published on July 14, 2026. Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.
When was CVE-2026-54121 disclosed?
CVE-2026-54121 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54121 actively exploited?
CVE-2026-54121 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 60.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54121?
CVE-2026-54121 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-54121?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54121, 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-2026-54121

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