CVE-2026-42901
CWE-346Published: May 22, 2026· Updated: May 27, 2026
Official Description
Origin validation error in Microsoft Entra ID allows an unauthorized attacker to elevate privileges over a network.
Risk Analysis
This critical vulnerability in Microsoft Entra ID allows an unauthorized attacker to elevate privileges over a network due to an origin validation error. With a perfect CVSS score of 10.0, this flaw poses an extremely severe risk, potentially leading to complete compromise of identity management systems.
No public exploit is currently known for this vulnerability. Its remote exploitability and low attack complexity indicate a high potential for exploitation if a working exploit is developed.
Users of Microsoft Entra ID should apply all available security updates and patches. Ensure proper configuration of origin validation and monitor for any suspicious authentication attempts.
Technical Analysis
CVE-2026-42901 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 10.0.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (1)
Quick Facts
Related CVEs (CWE-346)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-42901 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts