CVE-2026-28356
Description
multipart is a fast multipart/form-data parser for python. Prior to 1.2.2, 1.3.1 and 1.4.0-dev, the parse_options_header() function in multipart.py uses a regular expression with an ambiguous alternation, which can cause exponential backtracking (ReDoS) when parsing maliciously crafted HTTP or multipart segment headers. This can be abused for denial of service (DoS) attacks against web applications using this library to parse request headers or multipart/form-data streams. The issue is fixed in 1.2.2, 1.3.1 and 1.4.0-dev.
Risk Information
Base Score
7.5
MODERATE
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
Exploitation Probability
0.713
Associated Vulnerability
| Vulnerability | OS Platform |
|---|---|
| Vulnerabilities CVE-2026-28356 are fixed in Python-multipart 1.2.2 | Windows |
| Vulnerabilities CVE-2026-28356 are fixed in Python-multipart 1.3.1 | Windows |
| Vulnerabilities CVE-2026-28356 are fixed in Python-multipart for linux 1.2.2 | Linux |
| Vulnerabilities CVE-2026-28356 are fixed in Python-multipart for linux 1.3.1 | Linux |
Patch Details
No records foundReferences
https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234