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...