---
cve: "CVE-2026-53659"
severity: "HIGH"
cvss: 7.5
epss: "0.6%"
vendor: "http4k"
kev: false
exploited: false
published: "2026-09-14 18:17:51"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-02T22:21:01+02:00"
---

# CVE-2026-53659

> 7.5 HIGH · 🧪 PoC

## Beschreibung

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.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- e41f40814305510d4f82e30bb0bcd12b9928292e (Commit)
- 911eb36ed34ce8a8ec494f64044b9d49756ec45a (Commit)

## Referenzen

- <https://github.com/http4k/http4k/security/advisories/GHSA-g4w2-6h2r-3m3w>
- <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>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53659) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_