# CVE-2026-40347: python-multipart: Python-Multipart is a streaming multipart parser for Python

CVE-2026-40347 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-40347, released April 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-40347
- Priority: Routine
- CVSS: 5.3 (medium)
- EPSS: 0.0035
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 18, 2026

## Description

Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-multipart Debian 14 | 0.0.26-1 | [DEBIAN-CVE-2026-40347](https://patchblox.com/security/data/fix/linux/debian-cve-2026-40347.md) | Apr 18, 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 2026-11-08T06:59:42Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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