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.
History

Thu, 14 May 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 13 May 2026 22:45:00 +0000

Type Values Removed Values Added
First Time appeared Kludex
Kludex python-multipart
Vendors & Products Kludex
Kludex python-multipart

Wed, 13 May 2026 21:15:00 +0000

Type Values Removed Values Added
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.
Title Python-Multipart: Denial of Service via unbounded multipart part headers
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-05-13T20:55:11.767Z

Updated: 2026-05-14T19:52:12.815Z

Reserved: 2026-04-28T16:56:50.192Z

Link: CVE-2026-42561

cve-icon Vulnrichment

Updated: 2026-05-14T16:04:40.895Z

cve-icon NVD

Status : Deferred

Published: 2026-05-13T21:16:47.070

Modified: 2026-05-14T17:00:31.310

Link: CVE-2026-42561

cve-icon Redhat

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