CVE-2026-40379
Microsoft Enterprise Security Token Service (ESTS) Spoofing Vulnerability
CVSS Score
9.3
EPSS Score
0.0%
EPSS Percentile
0th
Exposure of sensitive information to an unauthorized actor in Azure Entra ID allows an unauthorized attacker to perform spoofing over a network.
| Vendor | microsoft |
| Product | microsoft enterprise security token service (ests) |
| Ecosystems | |
| Industries | TechnologyEnterprise |
| Published | May 12, 2026 |
| Last Updated | May 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
Microsoft / Microsoft Enterprise Security Token Service (ESTS)
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