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CVE-2026-42578

⚠️ high
🔍 Scan for this CVE
Summary

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 int

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.

CVSS Score
7.5
High
EPSS Score
0.0
Exploit Probability
Published Date
2026-05-13
First Seen: 2026-05-17
📊 Relative Risk Intelligence

This CVE is Moderate Risk - more severe than 69.0% of all 328,009 vulnerabilities in our database.

#101,817
Above average severity
Severity Percentile
🎯 CISA SSVC Assessment Updated: May 13, 2026
🔍 Exploitation Status
Poc
Proof-of-concept available
⚙️ Automatable
NO
Requires human interaction
💥 Technical Impact
Partial
Limited system impact
SSVC data provided by CISA
Last Modified 2026-05-18
Source NVD 🔗
CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS Vector 4.0 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE IDs (Weakness Types)
CWE-113

📦 Affected Products 2

Vendor Product Status Affected Versions
netty netty Affected
< 4.1.133
netty netty Affected
> 4.2.0 < 4.2.13

🔗 References 1

https://github.com/netty/netty/security/advisories/G...
Exploit Mitigation Vendor Advisory

🔗 Related CVEs 6

CVE ID Severity CVSS EPSS Summary Published
CVE-2026-44892 ⚠️ high 7.5 0.5 Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final,... 2026-06-12
CVE-2026-44893 ⚠️ high 7.5 0.6 Netty is a network application framework for development of protocol servers and clients. In netty-codec-haproxy prior t... 2026-06-12
CVE-2026-44894 ⚠️ high 7.5 0.2 Netty is a network application framework for development of protocol servers and clients. NoQuicTokenHandler is the toke... 2026-06-12
CVE-2026-45416 ⚠️ high 7.5 0.6 Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina... 2026-06-12
CVE-2026-45536 🔶 medium 4.0 0.2 Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina... 2026-06-12
CVE-2026-45673 🔶 medium 6.8 0.4 Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina... 2026-06-12
These CVEs affect the same products