What is CVE-2026-40347?

CVE-2026-40347 is a medium-severity vulnerability in Kludex Python-multipart, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2026-04-17.

How severe is CVE-2026-40347?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Resource exhaustion in Kludex Python-multipart

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…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (6.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Kludex Python-multipart — versions < 0.0.26

Weakness classification (CWE)

References

https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj (x_refsource_CONFIRM)
https://github.com/Kludex/python-multipart/releases/tag/0.0.26 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-40347?: CVE-2026-40347 is a medium-severity vulnerability in Kludex Python-multipart, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2026-04-17.
How severe is CVE-2026-40347?: Medium severity. CVSS v3 base score is 5.3 out of 10.