NetSight
IP …
high7.5

CVE-2026-42561

python-multipart has Denial of Service via unbounded multipart part headers

Impact

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.

Affected packages

EcosystemPackageAffectedFixed in
pippython-multipart< 0.0.270.0.27

Weakness classification

CWE-770CWE-606

References