CVE-2026-53540
LowCVSS 3.7Exploitation Probability (EPSS)
Low risk12th percentile — higher than 12% of all known CVEs
Summary
In the Python-Multipart library before version 0.0.31, the parse_form() function did not validate the Content-Length header before using it to bound its chunked read of the request body. A negative Content-Length turned the bounded read into a read-until-EOF, so the entire body was loaded into memory in a single read instead of in fixed-size chunks.
Risk Assessment
An attacker can send a request with a negative Content-Length header, causing excessive memory consumption and potential denial of service (DoS) on the server.
Recommendation
Update the Python-Multipart library to version 0.0.31 or later, which includes a fix that validates the Content-Length header.
Original NVD description (English source)
Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.31, parse_form() did not validate the Content-Length header before using it to bound its chunked read of the request body. A negative Content-Length turned the bounded read into a read-until-EOF, so the entire body was loaded into memory in a single read instead of in fixed-size chunks. This vulnerability is fixed in 0.0.31.