{"cve":"CVE-2026-53659","nvd":{"published":"2026-09-14T18:17:51.610","modified":"2026-09-30T19:57:08.043","status":"Deferred","description":"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 gzip-encoded request body that expands to gigabytes, exhausting the JVM heap and denying service to other clients. The fix uses SizeLimitedInputStream to enforce a default 10 MiB limit, causes ServerFilters.GZip and RequestFilters.GunZip to return 413 Request Entity Too Large, and causes other decompression paths to throw SizeLimitExceededException. This issue is fixed in versions 4.51.0.0, 5.42.0.0, and 6.49.0.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-409"],"references":["https://github.com/http4k/http4k/commit/2618fe08f9801353012561ae1f1382fa2d37bac9","https://github.com/http4k/http4k/commit/9f9e02f8efbbe04e0c70f1c46eef5d9d9067ea5b","https://github.com/http4k/http4k/releases/tag/6.49.0.0","https://github.com/http4k/http4k/security/advisories/GHSA-g4w2-6h2r-3m3w"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-53659","score":0.0063,"percentile":0.4988,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-g4w2-6h2r-3m3w","url":"https://osv.dev/vulnerability/GHSA-g4w2-6h2r-3m3w","summary":"http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` allowed memory-exhaustion DoS","modified":"2026-08-17T22:11:01.943230Z","packages":[{"ecosystem":"Maven","name":"org.http4k:http4k-core","purl":"pkg:maven/org.http4k/http4k-core","ranges":[">=6.0.0.0 <6.49.0.0"],"fixed":["6.49.0.0"]},{"ecosystem":"Maven","name":"org.http4k:http4k-core","purl":"pkg:maven/org.http4k/http4k-core","ranges":[">=5.0.0.0 <5.42.0.0"],"fixed":["5.42.0.0"]},{"ecosystem":"Maven","name":"org.http4k:http4k-core","purl":"pkg:maven/org.http4k/http4k-core","ranges":["<=4.48.2.0"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}