What is CVE-2026-40372?

CVE-2026-40372 is a critical-severity vulnerability in Microsoft Asp.net Core 10.0, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.1/10. Published 2026-04-21.

How severe is CVE-2026-40372?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Microsoft Asp.net Core 10.0

CVE-2026-40372

Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.

EPSS: 0.000 (6.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C.

Affected products

Microsoft Asp.net Core 10.0 — versions 10.0
Microsoft Visual Studio 2026 Version 18.5 — versions 18.5.0

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

ASP.NET Core Elevation of Privilege Vulnerability (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-40372?: CVE-2026-40372 is a critical-severity vulnerability in Microsoft Asp.net Core 10.0, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.1/10. Published 2026-04-21.
How severe is CVE-2026-40372?: Critical severity. CVSS v3 base score is 9.1 out of 10.