CVE-2026-42561
Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual part header. An attacker could send a request with either many repeated headers without terminating the header block or a single very large header value, causing excessive CPU work before request rejection or completion. This vulnerability is fixed in 0.0.27.
- CVSS 3.1
- 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-770, CWE-606
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-pp6c-gr5w-3c5g | PyPI | python-multipart | <0.0.27 | 0.0.27 |
| PYSEC-2026-3039 | PyPI | python-multipart | <0.0.27 | 0.0.27 |