CVE-2026-40347
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.
Published:Apr 17, 2026
Last Modified:Apr 24, 2026
EPS:Apr 17, 2026
EPSS Score:0.00019
CVSS Score:5.3
Affected Products
Vendor
Product
Action
Vendor
Fastapiexpert
Product
Python-multipart
Fastapiexpert
Python-multipart
Vendor
Kludex
Product
Python-multipart
Kludex
Python-multipart
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
