CVE-2026-40379
CRITICALMicrosoft Enterprise Security Token Service (ESTS) Spoofing Vulnerability
Title source: cnaDescription
Exposure of sensitive information to an unauthorized actor in Azure Entra ID allows an unauthorized attacker to perform spoofing over a network.
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
patch
Microsoft Enterprise Security Token Service (ESTS) Spoofing Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40379
Scores
CVSS v3
9.3
EPSS
0.0008
EPSS Percentile
23.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-200
Status
published
Products (3)
microsoft/entra_id
Microsoft/Microsoft Enterprise Security Token Service (ESTS)
-
Microsoft/Microsoft Entra
-
Published
May 12, 2026
Tracked Since
May 12, 2026