Vulnerability in Microsoft Asp.net Core
CVE-2026-40372
Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.008 (56.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.112 · newest: 0.008 · change: -0.104
Affected products
- Microsoft Asp.net Core
- Microsoft Asp.net Core 10.0 — versions 10.0
- Microsoft Visual Studio 2026 Version 18.5 — versions 18.5.0
Weakness classification (CWE)
References
- ASP.NET Core Elevation of Privilege Vulnerability (vendor-advisory, patch, Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-40372?
- CVE-2026-40372 is a critical-severity vulnerability in Microsoft Asp.net Core, 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.