Vulnerability in Microsoft.NETCore.App.Runtime.linux-x64 (CVE-2026-45491)
Summary
Vulnerability in Microsoft.NETCore.App.Runtime.linux-x64 (CVE-2026-45491). Data can be tampered with by attackers. Mitigation: upgrade to 10.0.9 or later.
Original description
The description as published by the source.
Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.
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-2026-45491 has been found in Microsoft.NETCore.App.Runtime.linux-x64.
Data can be tampered with by attackers. CVSS score: 6.2/10.
What to do: upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 10.0.9 or later.
If unsure, ask your IT team or search "Microsoft.NETCore.App.Runtime.linux-x64 CVE-2026-45491" on the vendor's site.
CVE-2026-45491 (Microsoft.NETCore.App.Runtime.linux-x64) — CWE-59 / CVSS v3 6.2
Attack vector: local / unauthenticated / no user interaction
Patched: 10.0.9 — 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-59) exists in Microsoft.NETCore.App.Runtime.linux-x64.
Check the vendor advisory for the affected versions of Microsoft.NETCore.App.Runtime.linux-x64.
Severity: Medium (CVSS 6.2/10). Data can be tampered with by attackers.
Update to 10.0.9.
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 'Microsoft.NETCore.App.Runtime.linux-x64' . 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
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1Identify exposure identify
grep -r 'Microsoft.NETCore.App.Runtime.linux-x64' . | 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
Microsoft.NETCore.App.Runtime.linux-x64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 Microsoft.NETCore.App.Runtime.linux-x64 to 10.0.9ステージング環境で 10.0.9 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-2026-45491 dotnet6
References
- advisory msrc.microsoft.com
- web github.com
- web nvd.nist.gov
- web github.com
- web github.com