io.netty/netty-handler: Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext

A flaw was found in Netty, an asynchronous, event-driven network application framework. An unauthenticated remote attacker can exploit fragmented Transport Layer Security TLS ClientHello messages to bypass the Server Name Indication SNI routing mechanism. This forces a fallback to a less secure...

RHLW-2026-313117B0CAD7329E Lightwell Security Advisory: netty-handler 4.1.100.Final-rhlw-00001

Red Hat Lightwell has released io.netty:netty-handler 4.1.100.Final-rhlw-00001 with backported fixes for CVE-2025-24970, CVE-2026-44249, CVE-2026-45416, CVE-2026-50010, CVE-2026-75595, and CVE-2026-75596. CVE-2025-24970: SslHandler doesn't correctly validate packets which can lead to native crash...

RHLW-2026-1CAAFB676CC0F4C9 Lightwell Security Advisory: netty-codec-http2 4.1.100.Final-rhlw-00001

Red Hat Lightwell has released io.netty:netty-codec-http2 4.1.100.Final-rhlw-00001 with backported fixes for CVE-2025-55163, CVE-2026-33871, CVE-2026-42587, CVE-2026-47244, CVE-2026-48043, CVE-2026-50560, CVE-2026-56819, and CVE-2026-59900. CVE-2025-55163: Netty MadeYouReset HTTP/2 DDoS...

CVE-2026-100659

A flaw was found in the Netty HTTP/3 codec. This vulnerability allows access control and request routing bypasses due to missing validation of destination headers. A remote, unauthenticated attacker can exploit this flaw by sending a Hypertext Transfer Protocol HTTP request containing conflicting...

EUVD-2026-87855

http4k Maven package org.http4k:http4k-core before 6.49.0.0, 5.42.0.0 and 4.51.0.0 uses substring Contains matching on the Host header by default in reverseProxy and reverseProxyRouting when dispatching to configured virtual hosts. If these functions are deployed as a public-facing inbound HTTP...

CVE-2026-100724 http4k before 6.49.0.0 Host Header Routing Bypass via reverseProxy

http4k Maven package org.http4k:http4k-core before 6.49.0.0, 5.42.0.0 and 4.51.0.0 uses substring Contains matching on the Host header by default in reverseProxy and reverseProxyRouting when dispatching to configured virtual hosts. If these functions are deployed as a public-facing inbound HTTP...

CVE-2026-100724 http4k before 6.49.0.0 Host Header Routing Bypass via reverseProxy

http4k Maven package org.http4k:http4k-core before 6.49.0.0, 5.42.0.0 and 4.51.0.0 uses substring Contains matching on the Host header by default in reverseProxy and reverseProxyRouting when dispatching to configured virtual hosts. If these functions are deployed as a public-facing inbound HTTP...

CVE-2026-100724 http4k before 6.49.0.0 Host Header Routing Bypass via reverseProxy

http4k Maven package org.http4k:http4k-core before 6.49.0.0, 5.42.0.0 and 4.51.0.0 uses substring Contains matching on the Host header by default in reverseProxy and reverseProxyRouting when dispatching to configured virtual hosts. If these functions are deployed as a public-facing inbound HTTP...

CVE-2026-100724

The http4k library (Maven package org.http4k:http4k-core) versions prior to 6.49.0.0 , 5.42.0.0 , and 4.51.0.0 are vulnerable to a Host Header Routing Bypass in the reverseProxy() and reverseProxyRouting() functions. The root cause is the use of substring (Contains) matching on the Host header wh...

CVE-2026-100659

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

UBUNTU-CVE-2026-100659

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659 Netty 4.2.0 through 4.2.17 HTTP/3 Request Routing Bypass

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

EUVD-2026-87753

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659 Netty 4.2.0 through 4.2.17 HTTP/3 Request Routing Bypass

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659 Netty 4.2.0 through 4.2.17 HTTP/3 Request Routing Bypass

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

CVE-2026-100659: Inconsistent Interpretation of HTTP Requests

Netty's HTTP/3 codec io.netty:netty-codec-http3 in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single...

PT-2026-99330

Name of the Vulnerable Software and Affected Versions netty-codec-http3 versions 4.2.0.Final through 4.2.17.Final Description The HTTP/3 codec fails to enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field must carry the same value when both are...

io.netty/netty-handler: Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext

A flaw was found in Netty, an asynchronous, event-driven network application framework. An unauthenticated remote attacker can exploit fragmented Transport Layer Security TLS ClientHello messages to bypass the Server Name Indication SNI routing mechanism. This forces a fallback to a less secure...