Vulnerability in dotnet (CVE-2026-42899)

Summary

vulnerability in dotnet (CVE-2026-42899). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to `8.0.27, 9.0.16, 10.0.8` or later.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **CVE-2026-42899** has been found in dotnet. Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10. What to do: upgrade dotnet to **8.0.27, 9.0.16, 10.0.8** or later. If unsure, ask your IT team or search "dotnet CVE-2026-42899" on the vendor's site.

CVE-2026-42899 (dotnet) — CWE-835 / CVSS v3 7.5 Attack vector: remote (network-reachable) / unauthenticated / no user interaction Patched: `8.0.27, 9.0.16, 10.0.8` — 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-835) exists in dotnet.

📍 Affected scope

dotnet — .

🔥 Severity

Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure

🔧 How to fix

Update to **8.0.27, 9.0.16, 10.0.8**.

🛡️ 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 'dotnet' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response Actions (7 steps)

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'dotnet' . | 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 `dotnet` を grep し、稼働しているサービス・バージョンを把握する。
6
Apply patch patch
```
Upgrade dotnet to 8.0.27, 9.0.16, 10.0.8
```
ステージング環境で 8.0.27, 9.0.16, 10.0.8 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
7
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 Step 3 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

Bitnami dotnet

[{"type":"SEMVER","events":[{"introduced":"8.0.0"},{"fixed":"8.0.27"},{"introduced":"9.0.0"},{"fixed":"9.0.16"},{"introduced":"10.0.0"},{"fixed":"10.0.8"}]}]

Bitnami dotnet-sdk

[{"type":"SEMVER","events":[{"introduced":"8.0.0"},{"fixed":"8.0.27"},{"introduced":"9.0.0"},{"fixed":"9.0.16"},{"introduced":"10.0.0"},{"fixed":"10.0.8"}]}]

nuget Microsoft.AspNetCore.App.Runtime.win-arm