---
cve: "CVE-2026-88975"
severity: "HIGH"
cvss: 7.5
epss: "0.6%"
vendor: "http4s"
kev: false
exploited: false
published: "2026-09-15 20:19:19"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-25T15:34:06+02:00"
---

# CVE-2026-88975

> 7.5 HIGH · 🧪 PoC

## Beschreibung

Http4s is a Scala interface for HTTP services. Prior to 0.23.37 and 1.0.0-M48, Ember’s HTTP/2 read loop parses a frame’s 24-bit declared length but waits to buffer the entire payload before comparing it with SETTINGS_MAX_FRAME_SIZE. An unauthenticated peer can declare a payload near 16 MiB on a connection where Ember advertised 16 KiB and either complete or slowly stream it, causing up to 1024-fold memory amplification per connection before processFrame can reject the frame. The shared H2Connection.readLoop affects withHttp2 servers and clients, while HTTP/2-disabled configurations are unaffected, and the patch rejects oversized frames before buffering their payloads. This issue is fixed in versions 0.23.37 and 1.0.0-M48.

## 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)

- 73340be10836b95241ed2d7682b4da057b7b5ccb (Commit)
- 2d62cbe12e8941ac4800a41fa45e132900b90caa (Commit)

## Referenzen

- <https://github.com/http4s/http4s/security/advisories/GHSA-gq9p-f254-h286>
- <https://github.com/http4s/http4s/commit/87cf334fa3f608ef7d3eb359e71e037ba3336d29>
- <https://github.com/http4s/http4s/releases/tag/v0.23.37>
- <https://github.com/http4s/http4s/releases/tag/v1.0.0-M48>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-88975) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_