CVE-2026-42578
📛 CVE Title
Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders 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. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- LOW
- CVSS score
- 2.9 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P- Effective score
- 2.9 / 10 LOW source: CNA overview
- CWE(s)
-
CWE-113 - Reserved
- 2026-04-28
- Published
- 2026-05-13 19:57 UTC
- Last updated
- 2026-05-13 20:37 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/42xxx/CVE-2026-42578.json
- Linked Threat
- CVE-2026-42578 — CVE-2026-42578
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-13 19:17:23 UTC
- NVD last modified
- 2026-05-18 12:54:04 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: nvd@nist.gov
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
- EPSS score
- 0.0001 (probability of exploitation in next 30 days)
- EPSS percentile
- 1.24% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 09:22 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-30121 - Assigner
- GitHub_M
- Published
- May 13, 2026, 5:57:43 PM
- Updated
- May 13, 2026, 6:37:18 PM
- EUVD base score (CVSS 4.0)
-
2.9 / 10
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P - EUVD-reported EPSS
- 0.0100
- Vendors
- netty
- Products
-
netty (< 4.1.133.Final)netty (4.2.0.Alpha1, < 4.2.13.Final)
- Aliases
-
GHSA-45q3-82m4-75jr
ENISA description: Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders 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. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| netty | netty |
>= 4.2.0.Alpha1, < 4.2.13.Final (affected),
< 4.1.133.Final (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr x_refsource_CONFIRM
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr x_refsource_CONFIRM
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-42578 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-42578 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr security-advisories@github.com ExploitMitigationVendor Advisory
- https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr 134c704f-9b21-4f2e-91b3-4a467353bcc0 ExploitMitigationVendor Advisory
Remediations (17)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:app.opencve.io
Remediation No vendor fix or workaround currently provided. OpenCVE Recommended Actions Upgrade Netty to version 4.2.13.Final or later or 4.1.133.Final or later to ensure HttpProxyHandler enforces header validation.
2026-05-23 20:54 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-23 20:54 UTC -
web:security.snyk.io
NVD Description Note:Versions mentioned in the description apply only to the upstream neo4j- 2026 .01 package and not the neo4j- 2026 .01 package as distributed by Chainguard.See How to fix ? for Chainguard relevant fixed versions and status. Netty is an asynchronous, event-driven network application framework.
2026-05-23 20:54 UTC -
web:techcommunity.microsoft.com
We wanted to tell you how to address the Exchange Server May 2026 vulnerability CVE - 2026 -42897.
2026-05-23 20:54 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-05-23 20:54 UTC -
web:www.helpnetsecurity.com
Microsoft has marked May 2026 Patch Tuesday by releasing fixes for 120+ CVE -numbered vulnerabilities, none of which are actively exploited.
2026-05-23 20:54 UTC -
web:www.resolvedsecurity.com
What is the Impact of CVE-2026-42578 ? Successful exploitation may allow attackers to achieve HTTP Header Injection, potentially bypassing proxy authentication, conducting request smuggling attacks, or manipulating proxy behavior. What is the Exploitability of CVE-2026-42578 ? Exploitation is of low complexity and can be performed remotely.
2026-05-23 20:54 UTC -
web:www.tenable.com
Netty has HTTP Header Injection via HttpProxyHandler Disabled Validation (Incomplete Fix CVE -2025-67735)
2026-05-23 20:54 UTC -
web:www.thehackerwire.com
CVE-2026-42578 is a High severity vulnerability (CVSS 7.5). Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with...
2026-05-23 20:54 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 20:54 UTC -
web:github.com
CVE - 2026 -44578 is a high-severity Server-Side Request Forgery (SSRF) vulnerability affecting self-hosted Next.js applications. Attackers can exploit crafted WebSocket Upgrade Requests to force the server into making outbound requests to internal or external systems.
2026-05-26 02:53 UTC -
web:learn.microsoft.com
Learning path Learn how Microsoft supports secure software development as part of a cybersecurity solution - Training Secure software development means integrating security into each phase of your development lifecycle, from requirements analysis to maintenance. Microsoft provides many services that can help you develop more secure code and deploy a more secure application in the cloud. This ...
2026-05-26 02:53 UTC -
web:thehackernews.com
Microsoft patched 138 flaws, including 30 Critical bugs, as AI discovery expands Patch Tuesday risk.
2026-05-26 02:53 UTC -
web:vulert.com
Microsoft's May 2026 Patch Tuesday fixes 138 vulnerabilities, including critical Windows DNS and Netlogon RCE flaws. Learn the risks, key CVEs , mitigation steps, and how Vulert can help.
2026-05-26 02:53 UTC -
web:www.computerworld.com
Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...
2026-05-26 02:53 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:53 UTC -
web:www.rapid7.com
Microsoft is publishing 77 vulnerabilities this Patch Tuesday, including two publicly disclosed zero-day vulnerabilities.
2026-05-26 02:53 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-42578.json.
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