What is CVE-2026-42901?

CVE-2026-42901 is a critical-severity vulnerability in Microsoft Entra_id, classified under Origin Validation Error. CVSS score: 10.0/10. Published 2026-05-22.

How severe is CVE-2026-42901?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Vulnerability in Microsoft Entra_id

CVE-2026-42901

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

EPSS: 0.000 (13.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Microsoft Entra_id
Microsoft Entra

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42901?: CVE-2026-42901 is a critical-severity vulnerability in Microsoft Entra_id, classified under Origin Validation Error. CVSS score: 10.0/10. Published 2026-05-22.
How severe is CVE-2026-42901?: Critical severity. CVSS v3 base score is 10.0 out of 10.