Improper Validation of Specified Quantity in Input Affecting python-multipart package, versions [,0.0.31)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-PYTHONMULTIPART-17345735
- published16 Jun 2026
- disclosed15 Jun 2026
- creditGanni Galea Curmi, Seokhee Chang
Introduced: 15 Jun 2026
CVE-2026-53540 (opens in a new tab)How to fix?
Upgrade python-multipart to version 0.0.31 or higher.
Overview
python-multipart is an A streaming multipart parser for Python
Affected versions of this package are vulnerable to Improper Validation of Specified Quantity in Input in the parse_form function when processing a negative Content-Length header. An attacker can cause excessive memory usage by sending a crafted request with a negative Content-Length, resulting in the entire request body being buffered in memory at once.
Note:
This is only exploitable if the application directly calls parse_form with a Content-Length header taken from attacker-controlled input and does not normalize negative values first.