CVE-2026-28356
HIGH EPSS 31.0%
Published Mar 12, 20263mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
Published Mar 12, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High
Threat Intelligence
EPSS Exploit Probability
31.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-1333
References 1
- github.com https://github.com/defnull/multipart/security/advisories/GHSA-p2m9-wcp5-6qw3
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.