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-2026-100724 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: Inconsistent Interpretation of HTTP Requests

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-2026-100725: Exposure of Sensitive Information to an Unauthorized Actor

http4k Maven artifact org.http4k:http4k-core before 6.48.0.0, 5.42.0.0, and 4.51.0.0 ships a BasicCookieStorage client-side cookie store used by ClientFilters.Cookies that does not enforce RFC 6265 scoping rules for the cookie domain, path, and Secure attributes. When a single BasicCookieStorage...

CVE-2026-100834: Authentication Bypass by Capture-replay

http4k's Digest authentication module org.http4k:http4k-security-digest before versions 6.48.0.0, 5.42.0.0 and 4.51.0.0 defaults the nonceVerifier parameter of ServerFilters.DigestAuth and DigestAuthProvider to true , so every nonce is accepted regardless of its value, age, or prior use...

CVE-2026-54147

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

CVE-2026-54148

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...

CVE-2026-54147

http4k-security-digest (a module of the Kotlin HTTP toolkit http4k) contains a bug in DigestAuthProvider.verify where the configured algorithm parameter is silently ignored and every digest response is verified with hardcoded MD5 , regardless of the intended algorithm. Deployments believing they ...

CVE-2026-54147 http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

CVE-2026-54147

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

CVE-2026-54147 http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

CVE-2026-54147 http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

EUVD-2026-83042

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefor...

CVE-2026-54148

http4k (a Kotlin HTTP toolkit) is vulnerable in the http4k-security-digest module. The DigestAuthProvider.verify method did not compare the uri parameter in an Authorization: Digest response with the actual request URL, meaning a captured valid Digest authentication response could be replayed aga...

CVE-2026-54148 http4k: `DigestAuthProvider.verify` did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...

CVE-2026-54148 http4k: `DigestAuthProvider.verify` did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...

CVE-2026-54148

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...

CVE-2026-54148 http4k: `DigestAuthProvider.verify` did not bind to request URI

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...

EUVD-2026-83039

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest...