Vulnerability in dotnet6 (UBUNTU-CVE-2026-62899)

Summary

Vulnerability in dotnet6 (UBUNTU-CVE-2026-62899). Confidential information can be exposed externally. Mitigation: upgrade to 8.0.130-8.0.30-0ubuntu1~22.04.1 or later.

Original description

The description as published by the source.

Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.

Source: OSV.dev (Open Source Vulnerabilities) OSV

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 UBUNTU-CVE-2026-62899 has been found in dotnet6.
Confidential information can be exposed externally.
What to do: upgrade dotnet6 to 8.0.130-8.0.30-0ubuntu1~22.04.1 or later.
If unsure, ask your IT team or search "dotnet6 UBUNTU-CVE-2026-62899" on the vendor's site.

UBUNTU-CVE-2026-62899 (dotnet6)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 8.0.130-8.0.30-0ubuntu1~22.04.1 — 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 (unclassified) exists in dotnet6.

📍 Affected scope

Check the vendor advisory for the affected versions of dotnet6.

🔥 Severity

Severity: ?. Confidential information can be exposed externally.

🔧 How to fix

Update to 8.0.130-8.0.30-0ubuntu1~22.04.1.

🛡️ 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 'dotnet6' . 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 'dotnet6' . | 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 dotnet6 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 dotnet6 to 8.0.130-8.0.30-0ubuntu1~22.04.1
```
ステージング環境で 8.0.130-8.0.30-0ubuntu1~22.04.1 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。

Affected packages

Ubuntu:22.04:LTS dotnet6

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:22.04:LTS dotnet7

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:22.04:LTS dotnet8

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.130-8.0.30-0ubuntu1~22.04.1"}]}]

Ubuntu:24.04:LTS dotnet10

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.0.111-10.0.11-0ubuntu1~24.04.1"}]}]

Ubuntu:24.04:LTS dotnet8

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.130-8.0.30-0ubuntu1~24.04.1"}]}]

Ubuntu:26.04:LTS dotnet10

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.0.111-10.0.11-0ubuntu1~26.04.1"}]}]

References

advisory ubuntu.com
report ubuntu.com
report cve.org
report msrc.microsoft.com
report devblogs.microsoft.com
report github.com