# CVE-2026-42561: python-multipart: Python-Multipart is a streaming multipart parser for Python

CVE-2026-42561 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-42561, released May 13, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-42561
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0074
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 13, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-multipart Debian 14 | 0.0.32-1 | [DEBIAN-CVE-2026-42561](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42561.md) | May 13, 2026 |
| Linux | python-python-multipart sles 16.0 | 0.0.20-160000.4.1 | [SUSE-SU-2026:21999-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-21999-1.md) | May 29, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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