Vulnerability

CVE-2026-55040

Descriptive record received from OpenCTI and minimised for consultation in the Intel portal.

Sharing: TLP:CLEAR
Confidence: 100
Source: Cybersecurity and Infrastructure Security Agency
Updated: 26/09/2026 04:06

Description

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

STIX identifiervulnerability--5bc728f0-8ab0-5917-91b2-28ee7a1d9b66

First observation-

Last observation-

Known relationships9

Aliases and classifications

CWE-1390Weak Authentication

Minimised technical details

No raw data

cvss score: 9.1
cvss vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
cvss severity: CRITICAL
cisa kev: True

Provenance

Public references

Microsoft SharePoint Server Security Feature Bypass Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040

EudorIA correlation

Intel catalogue

The vulnerability is also available in the EudorIA editorial catalogue.

Open EudorIA analysis

Presence in OpenCTI describes an intelligence correlation and does not, by itself, constitute evidence of compromise, legal attribution or operational guidance applicable without context verification.