CVE-2026-55040 (GCVE-0-2026-55040)

Vulnerability from cvelistv5 – Published: 2026-07-14 17:09 – Updated: 2026-08-13 13:16
VLAI KEVIntel
Title
Microsoft SharePoint Server Security Feature Bypass Vulnerability
Summary
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
SSVC
Exploitation: poc Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-13 03:55 UTC
CWE
Assigner
Impacted products
Date Public
2026-07-14 14:00
KEVIntel
Known Exploited Vulnerability - GCVE BCP-07 Compliant

Vulnerability ID: CVE-2026-55040

Status: Confirmed

Status Updated: 2026-08-12 19:37 UTC

Exploited: Yes


Timestamps
First Seen: 2026-08-12
Asserted: 2026-08-12

Scope
Notes: Microsoft SharePoint Server Security Feature Bypass Vulnerability | Affected: Microsoft / Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition | CVSS: 9.1 (CRITICAL) | EPSS: 0.01626 | Used in malware: unknown | Not yet in CISA KEV: True

Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel


Details
Feed KEVIntel (kevintel.com)
Title Microsoft SharePoint Server Security Feature Bypass Vulnerability
Vendor Microsoft
Product Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition
Added Date 2026-08-12T19:37:46.763Z
Cvss Score 9.1
Epss Score 0.01626
Cvss Severity CRITICAL
Epss Percentile 0.73981
Used In Malware unknown
Ahead Of Cisa Kev None
Not Yet In Cisa Kev True

References

Created: 2026-08-12 20:00 UTC | Updated: 2026-08-12 20:00 UTC
Show details on NVD website

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
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