---
cve: "CVE-2026-42561"
severity: "HIGH"
cvss: 7.5
epss: "74%"
vendor: "Kludex"
kev: false
exploited: false
published: "2026-05-13 21:16:47"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T02:40:55+02:00"
---

# CVE-2026-42561

> 7.5 HIGH · 🧪 PoC

## Beschreibung

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual part header. An attacker could send a request with either many repeated headers without terminating the header block or a single very large header value, causing excessive CPU work before request rejection or completion. This vulnerability is fixed in 0.0.27.

## 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)

- 6d1d6892a6b01b25da6f3e7b097e8e06c57fb250 (Commit)

## Referenzen

- <https://github.com/Kludex/python-multipart/security/advisories/GHSA-pp6c-gr5w-3c5g>
- <https://access.redhat.com/errata/RHSA-2026:37275>
- <https://access.redhat.com/errata/RHSA-2026:42132>
- <https://access.redhat.com/errata/RHSA-2026:42142>
- <https://access.redhat.com/errata/RHSA-2026:43038>
- <https://access.redhat.com/errata/RHSA-2026:44696>
- <https://access.redhat.com/errata/RHSA-2026:51194>
- <https://access.redhat.com/errata/RHSA-2026:51219>
- <https://access.redhat.com/errata/RHSA-2026:51357>
- <https://access.redhat.com/security/cve/CVE-2026-42561>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2477309>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42561.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-42561) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_