Resource exhaustion in Kludex Python-multipart

CVE-2026-53539

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remainin…

Vulnerability class: DoS (Denial of Service)

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53539?
CVE-2026-53539 is a high-severity vulnerability in Kludex Python-multipart, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-22.
How severe is CVE-2026-53539?
High severity. CVSS v3 base score is 7.5 out of 10.