CVE-2026-40347

5.3 MEDIUM
Published: April 18, 2026 Modified: April 24, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/Kludex/python-multipart/releases/tag/0.0.26
Source: security-advisories@github.com
Product Release Notes

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.3 / 10.0
EPSS (Exploit Probability)
0.4%
27th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

fastapiexpert