Cyber Resilience

CVE-2026-42901

Critical

Published: 22 May 2026

Published
22 May 2026
Modified
27 May 2026
KEV Added
—
Patch
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CVSS Score v3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0030 21.8th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-42901 is a critical-severity Origin Validation Error (CWE-346) vulnerability in Microsoft Entra Id. Its CVSS base score is 10.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability details

Origin validation error in Microsoft Entra ID allows an unauthorized attacker to elevate privileges over a network.

CWE(s)
CWE-346

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1078.004 Cloud Accounts Stealth
Valid accounts in cloud environments may allow adversaries to perform actions to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
Why these techniques?

Origin validation error (CWE-346) in Entra ID directly enables network-based unauthorized privilege escalation on cloud accounts.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

microsoft
entra id
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

IA-9 Service Identification and Authentication
addresses: CWE-346

Requires unique identification of the service before communications, addressing failures to validate the origin of the interaction.

SC-11 Trusted Path
addresses: CWE-346

Trusted path establishment enforces validation that the communication originates from and reaches only the intended trusted system components.

SC-20 Secure Name/Address Resolution Service (Authoritative Source)
addresses: CWE-346

Enforces validation of the true origin of DNS responses via signatures and chain-of-trust mechanisms.

SC-21 Secure Name/Address Resolution Service (Recursive or Caching Resolver)
addresses: CWE-346

Enforces origin validation of name/address data, eliminating reliance on unverified or impersonated DNS sources.

SC-23 Session Authenticity
addresses: CWE-346

Mandates origin validation so that only legitimate endpoints can continue the authenticated session.

References