CVE-2026-53540

Python-Multipart: Negative Content-Length in parse_form buffers the entire body in memory

At a glance

Severity
LOW 3.7
EPSS
EPSS 0.34 % · percentile 28 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Analyzed

Description

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.31, parse_form() did not validate the Content-Length header before using it to bound its chunked read of the request body. A negative Content-Length turned the bounded read into a read-until-EOF, so the entire body was loaded into memory in a single read instead of in fixed-size chunks. This vulnerability is fixed in 0.0.31.

Scores

VersionScoreVectorScored by
CVSS 3.1LOW 3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LGitHub_M
CVSS 3.1LOW 3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LNVD · security-advisories@github.com (Secondary)

Weaknesses (CWE)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Kludex · python-multipartaffected < 0.0.31

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD