CVE-2026-40347
Python-Multipart affected by Denial of Service via large multipart preamble or epilogue data
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-400 CWE-834 |
| Vendor | kludex |
| Product | python-multipart |
| Published | Apr 17, 2026 |
Stay Ahead of the Next One
Get instant alerts for kludex python-multipart
Be the first to know when new medium vulnerabilities affecting kludex python-multipart are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
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
Affected Versions
Kludex / python-multipart
< 0.0.26