low3.7
CVE-2026-53540
python-multipart: Negative Content-Length in parse_form buffers the entire body in memory
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | python-multipart | < 0.0.31 | 0.0.31 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Fastapiexpert | Python-Multipart | before 0.0.31 |