Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-42578 high CVSS 7.5

Vulnerability in io.netty:netty-handler-proxy (CVE-2026-42578)

Summary

Vulnerability in io.netty:netty-handler-proxy (CVE-2026-42578). Data can be tampered with by attackers. Exploitable via io.netty.handler.proxy.HttpProxyHandler. Mitigation: upgrade to 4.2.13.Final or later.

Original description

The description as published by the source.

Security Vulnerability Report: HTTP Header Injection via HttpProxyHandler Disabled Validation in Netty

1. Vulnerability Summary

Field Value
Product Netty
Version 4.2.12.Final (and all prior versions)
Component io.netty.handler.proxy.HttpProxyHandler
Vulnerability Type CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers
Impact HTTP Header Injection in CONNECT Proxy Requests
CVSS 3.1 Score 7.5 (High)
CVSS 3.1 Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Related Advisory GHSA-84h7-rjj3-6jx4 (Incomplete Fix)

2. Affected Components

  • io.netty.handler.proxy.HttpProxyHandler — newInitialMessage() method (line 176) explicitly disables header validation via withValidation(false)

3. Vulnerability Description

Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method (line 176) creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders (line 188-190) without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server.

Root Cause

// HttpProxyHandler.java:176-190
protected Object newInitialMessage(ChannelHandlerContext ctx) throws Exception {
    // ...
    Ht…

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-2026-42578 has been found in io.netty:netty-handler-proxy.
Attackers can target a specific entry point like io.netty.handler.proxy.HttpProxyHandler over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: upgrade io.netty:netty-handler-proxy to 4.2.13.Final or later.
If unsure, ask your IT team or search "io.netty:netty-handler-proxy CVE-2026-42578" on the vendor's site.

CVE-2026-42578 (io.netty:netty-handler-proxy) — CWE-113 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: io.netty.handler.proxy.HttpProxyHandler / HttpProxyHandler / outboundHeaders / DefaultHttpRequest
Patched: 4.2.13.Final — 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-113) exists in io.netty:netty-handler-proxy. Attackers reach the vulnerable code path via io.netty.handler.proxy.HttpProxyHandler without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of io.netty:netty-handler-proxy. Attack surface: io.netty.handler.proxy.HttpProxyHandler / HttpProxyHandler / outboundHeaders / DefaultHttpRequest.

🔥 Severity

Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.

🔧 How to fix

Update to 4.2.13.Final.

🛡️ 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. Audit SBOM/dependencies to find affected services.

Response actions

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

  1. 1
    Identify exposure identify 
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで io.netty:netty-handler-proxy を使っているサービスとバージョンを洗い出す。

  2. 2
    Apply patch patch 
    Upgrade io.netty:netty-handler-proxy to 4.2.13.Final

    ステージング環境で 4.2.13.Final 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. 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

maven io.netty:netty-handler-proxy
[{"type":"ECOSYSTEM","events":[{"introduced":"4.2.0.Alpha1"},{"fixed":"4.2.13.Final"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details