CVE-2026-70175 high CVSS 8.1

Vulnerability in Microsoft.AspNetCore.App.Runtime.linux-arm (CVE-2026-70175)

Summary

Vulnerability in Microsoft.AspNetCore.App.Runtime.linux-arm (CVE-2026-70175). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 8.0.32 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 Microsoft.AspNetCore.Identity and Microsoft.AspNetCore.Identity.UI. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

ASP.NET Core Identity password-reset and confirmation flows can send mail to the unvalidated request address instead of the user's stored canonical address.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/457

CVSS Details

Version: 3.1
Severity: High
Score: 8.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-640 (Weak Password Recovery Mechanism for Forgotten Password)

Affected Platforms

Platforms: Windows, Linux, macOS
Architectures: All

Affected Packages

The vulnerability affects Microsoft .NET projects that use an affected package version listed below.

Package name	Affected version	Patched version
Microsoft.AspNetCore.App.Runtime.linux-arm	>= 9.0.0, <= 9.0.20	9.0.21
Microsoft.AspNetCore.App.Runtime.linux-arm64	>= 9.0.0, <= 9.0.20	9.0.21
[Microsoft.AspNetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Micro…

Source: GitHub Security Advisories (Global) 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-2026-70175 has been found in Microsoft.AspNetCore.App.Runtime.linux-arm.
Successful exploitation can lead to full system takeover. CVSS score: 8.1/10.
What to do: upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 8.0.32 or later.
If unsure, ask your IT team or search "Microsoft.AspNetCore.App.Runtime.linux-arm CVE-2026-70175" on the vendor's site.

CVE-2026-70175 (Microsoft.AspNetCore.App.Runtime.linux-arm) — CWE-640 / CVSS v3 8.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 8.0.32 — 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-640) exists in Microsoft.AspNetCore.App.Runtime.linux-arm.

📍 Affected scope

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

🔥 Severity

Severity: High (CVSS 8.1/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 8.0.32.

🛡️ 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.AspNetCore.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.AspNetCore.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.AspNetCore.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.AspNetCore.App.Runtime.linux-arm to 8.0.32
```
ステージング環境で 8.0.32 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。