CVE-2026-55040

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-14. the CNA's CVSS baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

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

Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.

CVSS v3
9.1
EG Score
9.1(high)
EPSS
48.1%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 22, 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-2026-55040

Vendor Advisories for CVE-2026-55040(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 26× in last 7d / 42× 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. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:52 UTCEG score recompute
  7. 2026-07-19 02:52 UTCVendor advisory
  8. 2026-07-19 02:52 UTCGHSA enrichment
  9. 2026-07-19 02:29 UTCEPSS rescore
  10. 2026-07-18 10:04 UTCEPSS rescore
  11. 2026-07-17 04:28 UTCVendor advisory
  12. 2026-07-17 04:28 UTCGHSA enrichment
  13. 2026-07-17 00:17 UTCVendor advisory
  14. 2026-07-17 00:17 UTCGHSA enrichment
  15. 2026-07-16 20:05 UTCVendor advisory
  16. 2026-07-16 20:05 UTCGHSA enrichment
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-16 15:53 UTCVendor advisory
  19. 2026-07-16 15:53 UTCGHSA enrichment
  20. 2026-07-16 11:41 UTCGHSA enrichment
  21. 2026-07-16 07:30 UTCVendor advisory
  22. 2026-07-16 07:30 UTCGHSA enrichment
  23. 2026-07-16 03:19 UTCVendor advisory
  24. 2026-07-16 03:19 UTCGHSA enrichment
  25. 2026-07-15 23:08 UTCVendor advisory
Show 17 more
  1. 2026-07-15 23:08 UTCGHSA enrichment
  2. 2026-07-15 18:56 UTCVendor advisory
  3. 2026-07-15 18:56 UTCGHSA enrichment
  4. 2026-07-15 16:57 UTCEPSS rescore
  5. 2026-07-15 16:57 UTCEPSS rescore
  6. 2026-07-15 14:44 UTCVendor advisory
  7. 2026-07-15 14:44 UTCGHSA enrichment
  8. 2026-07-15 10:31 UTCVendor advisory
  9. 2026-07-15 10:31 UTCGHSA enrichment
  10. 2026-07-15 06:18 UTCVendor advisory
  11. 2026-07-15 06:18 UTCGHSA enrichment
  12. 2026-07-15 02:06 UTCGHSA enrichment
  13. 2026-07-14 21:54 UTCVendor advisory
  14. 2026-07-14 21:54 UTCGHSA enrichment
  15. 2026-07-14 17:43 UTCEG score recompute
  16. 2026-07-14 17:43 UTCVendor advisory
  17. 2026-07-14 17:40 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55040?
CVE-2026-55040 is a critical vulnerability published on July 14, 2026. Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
When was CVE-2026-55040 disclosed?
CVE-2026-55040 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-2026-55040 actively exploited?
CVE-2026-55040 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 48.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55040?
CVE-2026-55040 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-55040?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55040, 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-2026-55040

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