Vulnerability in aspnet-core (CVE-2026-40372)
Summary
Vulnerability in aspnet-core (CVE-2026-40372). Confidential information can be exposed externally. Mitigation: upgrade to 10.0.7 or later.
Original description
The description as published by the source.
Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-40372 has been found in aspnet-core.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade aspnet-core to 10.0.7 or later.
If unsure, ask your IT team or search "aspnet-core CVE-2026-40372" on the vendor's site.
CVE-2026-40372 (aspnet-core) — CWE-347 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 10.0.7 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-347) exists in aspnet-core.
Check the vendor advisory for the affected versions of aspnet-core.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 10.0.7.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'aspnet-core' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'aspnet-core' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
aspnet-coreを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade aspnet-core to 10.0.7ステージング環境で 10.0.7 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-40372 dotnet7
References
- advisory msrc.microsoft.com
- report bugzilla.redhat.com
- web access.redhat.com
- web security.access.redhat.com
- web nvd.nist.gov