CVE-2026-40347

MEDIUM EPSS 27.0%
Published Apr 18, 20262mo ago · Modified Jun 17, 20262w ago
5.3 CVSS 3.1
Medium
Find Similar
Published Apr 18, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.3
Exploitability
3.9
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability Low

Threat Intelligence

EPSS Exploit Probability
27.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-400 Uncontrolled Resource Consumption Resource Mgmt
CWE-834

Affected Products 1

VendorProductVersionRange
fastapiexpertpython-multipart* <0.0.26

References 2

  • github.com https://github.com/Kludex/python-multipart/releases/tag/0.0.26
    ProductRelease Notes
  • github.com https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.