CVE-2026-50528 high CVSS 8.2

Vulnerability in Microsoft.NetCore.App.Runtime.linux-arm (CVE-2026-50528)

Summary

Vulnerability in Microsoft.NetCore.App.Runtime.linux-arm (CVE-2026-50528). Data can be tampered with by attackers. Mitigation: upgrade to 8.0.29 or later.

Original description

The description as published by the source.

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET TLS/SSL (System.Net.Security). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A security feature bypass vulnerability exists in .NET 8, .NET 9, and .NET 10 when processing TLS/SSL connections. An attacker can exploit the SslStream implementation to bypass authorization checks during secure communication.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/**TBD**

CVSS Details

Version: 3.1
Severity: High
Score: 8.2
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Weakness: CWE-863 (Incorrect Authorization)

Affected Platforms

Platforms: All
Architectures: All

Affected Packages

The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below

.NET 10.0

Package name	Affected version	Patched version
Microsoft.NetCore.App.Runtime.linux-arm	>= 10.0.0, <= 10.0.9	10.0.10
Microsoft.NetCore.App.Runtime.linux-arm64	>= 10.0.0, <= 10.0.9	10.0.10
[Microsoft.NetCore.App.Runtime.linux-musl…

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-2026-50528 has been found in Microsoft.NetCore.App.Runtime.linux-arm.
Data can be tampered with by attackers. CVSS score: 8.2/10.
What to do: upgrade Microsoft.NetCore.App.Runtime.linux-arm to 8.0.29 or later.
If unsure, ask your IT team or search "Microsoft.NetCore.App.Runtime.linux-arm CVE-2026-50528" on the vendor's site.

CVE-2026-50528 (Microsoft.NetCore.App.Runtime.linux-arm) — CWE-302 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 8.0.29 — 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-302) 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 8.2/10). Data can be tampered with by attackers.

🔧 How to fix

Update to 8.0.29.

🛡️ 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 8.0.29
```
ステージング環境で 8.0.29 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。