CVE-2026-40372 | ASP.NET Core Elevation of Privilege Vulnerability

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

Published: 2026-04-21 Last update: 2026-04-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40372 is rated High Risk (74.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 10.35%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +10.31% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-40372

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 10.35% +10.31%
2 2026-04-22 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40372

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 5.2 [email protected]

Weakness enumeration for CVE-2026-40372

GitHub Security Advisory for CVE-2026-40372

GHSA-9mv3-2cwr-p262 · Severity: critical · Ecosystem: nuget — Microsoft Security Advisory CVE-2026-40372 – ASP.NET Core Elevation of Privilege

OS Trackers for CVE-2026-40372

vendor priority summary link
redhat critical — https://access.redhat.com/security/cve/CVE-2026-40372
ubuntu medium CVE-2026-40372 medium priority: Ubuntu including 5 source packages (dotnet10, dotnet6, dotnet7, dotnet8, dotnet9), 41 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 27, not-affected 5, needs-triage 4, released 4, ignored 1. https://ubuntu.com/security/CVE-2026-40372

Affected software / configurations for CVE-2026-40372

Vendor Product Version Raw CPE
microsoft asp.net_core >= 10.0.0, < 10.0.7 cpe:2.3:a:microsoft:asp.net_core:*:*:*:*:*:*:*:*

References for CVE-2026-40372

cvelogic Threat Intelligence