Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-42578
Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation
AV AC AT PR UI VC VI VA CVSS EPSS %ile KEV
N L P N N N L N 2.9 .0115 65.9 —
AFFECTED
Product Versions Fixed
netty >= 4.2.0.Alpha1, < 4.2.13.Final – —
TIMELINE
Apr 28 Reserved by GitHub_M
May 13 Published (CNA: GitHub_M)
Aug 13 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
Sep 7 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
Sep 9 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
Sep 11 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
Sep 17 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
Sep 18 EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added.
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.
Lifecycle
Complete event history — 8 events, chronological
| Date | Event | Detail |
|---|
| April 28, 2026 | Reserved | Reserved by GitHub_M |
| May 13, 2026 | Published | Published (CNA: GitHub_M) |
| August 13, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
| September 7, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
| September 9, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
| September 11, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
| September 17, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
| September 18, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-42578 (netty). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| netty | netty | — | >= 4.2.0.Alpha1, < 4.2.13.Final | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-42578 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
