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Fencer Intel
critical 9.1

CVE-2026-40372 in the critical feed json

ASP.NET Core Elevation of Privilege Vulnerability

published 6mo ago modified 14d ago also BIT-aspnet-core-2026-40372 , EUVD-2026-24249 , GHSA-9mv3-2cwr-p262

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
11.2%
EPSS 11.2% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

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

Patch / fix

  • nuget Microsoft.AspNetCore.DataProtection 10.0.7
  • bitnami aspnet-core 10.0.7
  • Microsoft ASP.NET Core 10.0 10.0.7
  • Microsoft Microsoft Visual Studio 2026 version 18.5 18.5.2
  • dotnet10 Ubuntu 24.04 LTS 10.0.107-10.0.7-0ubuntu1~24.04.1
  • dotnet10 Ubuntu 25.10 10.0.107-10.0.7-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 26.04 LTS 10.0.107-10.0.7-0ubuntu1~26.04.1

ubuntu advisories UBUNTU-CVE-2026-40372

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dotnet10-runtime Alpine 3.24, Alpine 3.23 10.0.7-r0

alpine advisories ALPINE-CVE-2026-40372

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-40372 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40372 updated cvss 9.1

ASP.NET Core: ASP.NET: ASP.NET Core: Privilege escalation via improper cryptographic signature verification

  • Red Hat Enterprise Linux 8 dotnet, dotnet-host, dotnet-sdk-10.0, dotnet-hostfxr-10.0, dotnet-runtime-10.0, dotnet-sdk-aot-10.0, +10 more Red Hat Enterprise Linux 9 dotnet-host, dotnet-sdk-10.0, dotnet-hostfxr-10.0, dotnet-runtime-10.0, dotnet-sdk-aot-10.0, dotnet-sdk-dbg-10.0, +9 more Red Hat Enterprise Linux 10 dotnet10.0 10.0.109-2.el10 Red Hat Hardened Images dotnet10.0 10.0.109-2.el10
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
6mo ago

Exploit prediction

11.21% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 9.1 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
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
nuget Microsoft.AspNetCore.DataProtection
>=10.0.0, <10.0.7
10.0.7
bitnami aspnet-core
>=10.0.0, <10.0.7
10.0.7

Affected products

  • Microsoft ASP.NET Core 10.0
  • Microsoft Microsoft Visual Studio 2026 version 18.5
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Hardened Images

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.