CVE-2024-53981: python-multipart is a streaming multipart parser for Python. When parsing form data, python-multipart skips line breaks (CR \r or LF \n) in front of t...

Description

python-multipart is a streaming multipart parser for Python. When parsing form data, python-multipart skips line breaks (CR \r or LF \n) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs. An attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS). This vulnerability is fixed in 0.0.18.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.63%

45.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

References

Timeline

Published: Dec 2, 2024
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2024-53981?

python-multipart is a streaming multipart parser for Python. When parsing form data, python-multipart skips line breaks (CR \r or LF \n) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs. An attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS). This vulnerability is fixed in 0.0.18.

How severe is CVE-2024-53981?

CVE-2024-53981 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.63% probability of exploitation in the next 30 days.

How do I fix CVE-2024-53981?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.