CVE-2026-53540
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.
- CVSS 3.1
- 3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 27% of CVEs (scores of 2026-10-25)
- CWE
- CWE-1284
- Published
- Modified
- Record from
- the NVD, synced
Affected
- fastapiexpert:python-multipart
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-v9pg-7xvm-68hf | PyPI | python-multipart | <0.0.31 | 0.0.31 |
| PYSEC-2026-3040 | PyPI | python-multipart | <0.0.31 | 0.0.31 |