CVE-2026-62909 high CVSS 7.8

Vulnerability in Microsoft.NETCore.App.Runtime.linux-arm (CVE-2026-62909)

Summary

Vulnerability in Microsoft.NETCore.App.Runtime.linux-arm (CVE-2026-62909). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 8.0.30 or later.

Original description

The description as published by the source.

Uncaught exception in .NET allows an authorized attacker to elevate privileges 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-2026-62909 has been found in Microsoft.NETCore.App.Runtime.linux-arm.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: upgrade Microsoft.NETCore.App.Runtime.linux-arm to 8.0.30 or later.
If unsure, ask your IT team or search "Microsoft.NETCore.App.Runtime.linux-arm CVE-2026-62909" on the vendor's site.

CVE-2026-62909 (Microsoft.NETCore.App.Runtime.linux-arm) — CWE-252 / CVSS v3 7.8
Attack vector: local / no user interaction
Patched: 8.0.30 — 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.

❓ What is the problem

A vulnerability (CWE-252) exists in Microsoft.NETCore.App.Runtime.linux-arm.

📍 Affected scope

Check the vendor advisory for the affected versions of Microsoft.NETCore.App.Runtime.linux-arm.

🔥 Severity

Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 8.0.30.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Microsoft.NETCore.App.Runtime.linux-arm' . 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

1
Identify exposure identify
```
grep -r 'Microsoft.NETCore.App.Runtime.linux-arm' . | 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-arm を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 8.0.30
```
ステージング環境で 8.0.30 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。
3
Post-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。