CVE-2026-54148: Authentication Bypass by Capture-replay

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: Use of a Broken or Risky Cryptographic Algorithm

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-2026-53659

A flaw was found in http4k, a functional toolkit for Kotlin HTTP applications. The ServerFilters.GZip and RequestFilters.GunZip functions, along with underlying Gzip request-body decompression, do not limit the decompressed size of incoming data. An unauthenticated client can exploit this by...

PT-2026-92403

The static content handlers ResourceService and WebjarService URL decode each path segment and then reject only segments that are exactly "", ".", or "..". A percent-encoded separator %2F lets an attacker smuggle a ../ segment past that filter and escape the configured base, reading resources tha...

CVE-2026-53659

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

CVE-2026-53659 http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` allowed memory-exhaustion DoS

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

CVE-2026-53659

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

com.apollographql.execution:apollo-execution-http4k (0.1.2), com.apollographql.execution:apollo-execution-http4k-jvm (0.1.2) +356 more potentially affected by CVE-2026-53659 via org.http4k:http4k-core (>=6.0.0.0, <=6.48.0.0)

org.http4k:http4k-core MAVEN version =6.0.0.0, =0.6.0, =0.1.1, =0.1.1, =0.1.1, =2.1.2-beta1, =4.0.0-rc27, =2.1.2-beta1, =2.1.2-beta1, =4.0.0-rc27, =2.1.2-beta1, =2.1.2-beta1, =5.3.1 and more Source cves: CVE-2026-53659 Source advisory: MEND:CVE-2026-53659...

CVE-2026-53659 http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` allowed memory-exhaustion DoS

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

CVE-2026-53659

http4k is a functional Kotlin HTTP toolkit. The vulnerability (CWE-409) exists in ServerFilters.GZip , RequestFilters.GunZip , and the underlying gzip decompression functions, which imposed no cap on decompressed size . An unauthenticated client can send a small gzip-encoded request body that exp...

CVE-2026-53659 http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` allowed memory-exhaustion DoS

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

com.apollographql.execution:apollo-execution-http4k (>=0.0.2, <=0.1.1), com.apollographql.execution:apollo-execution-http4k-jvm (>=0.0.2, <=0.1.1) +333 more potentially affected by CVE-2026-53659 via org.http4k:http4k-core (>=5.0.0.0, <=5.41.0.0)

org.http4k:http4k-core MAVEN version =5.0.0.0, =0.0.2, =0.0.2, =0.0.1, =1.3.0, =1.3.0, =1.3.0, =1.3.0, =0.5.0, =1.30.0, =0.1, =0.1.1 and more Source cves: CVE-2026-53659 Source advisory: MEND:CVE-2026-53659...

EUVD-2026-77694

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

CVE-2026-53659: Improper Handling of Highly Compressed Data (Data Amplification)

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small...

URI Validation Bypass

http4k-security-digest is vulnerable to URI Validation Bypass. The vulnerability is due to the client not validating the uri parameter in the Digest authentication response against the actual request URL, which allows an attacker to replay a captured authentication response against other URLs...

http4k: `DigestAuthProvider.verify` did not bind to request URI

Impact An issue in DigestAuthProvider.verify: The uri parameter in the client's Authorization: Digest … response was not checked against the actual request URL. A captured Digest authentication response could be replayed against any other URL served by the same realm, breaking the per-request-URL...

GHSA-P28P-J94Q-PG32 http4k: `DigestAuthProvider.verify` did not bind to request URI

Impact An issue in DigestAuthProvider.verify: The uri parameter in the client's Authorization: Digest … response was not checked against the actual request URL. A captured Digest authentication response could be replayed against any other URL served by the same realm, breaking the per-request-URL...

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

Impact An issue in DigestAuthProvider.verify: Algorithm silently forced to MD5. The configured algorithm parameter was ignored — every verification used MD5 regardless of configuration. Deployments believing they were running SHA-256 Digest auth were silently inheriting MD5's collision weaknesses...

GHSA-VXXM-WWQH-MH47 http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI

Impact An issue in DigestAuthProvider.verify: Algorithm silently forced to MD5. The configured algorithm parameter was ignored — every verification used MD5 regardless of configuration. Deployments believing they were running SHA-256 Digest auth were silently inheriting MD5's collision weaknesses...

org.http4k:http4k-aws (3.133.0), org.http4k:http4k-client-apache (3.133.0) +31 more potentially affected by CVE-2026-53659 via org.http4k:http4k-core (3.133.0)

org.http4k:http4k-core MAVEN version 3.133.0 is affected by a known vulnerability. The following packages have a transitive dependency on org.http4k:http4k-core and may be impacted: - org.http4k:http4k-aws 3.133.0 - org.http4k:http4k-client-apache 3.133.0 - org.http4k:http4k-client-apache-async...