CVE-2026-53540

Name	CVE-2026-53540
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-multipart (PTS)	bullseye	0.0.5-2	vulnerable
	bookworm	0.0.5-3	vulnerable
	trixie	0.0.20-1.1~deb13u1	vulnerable
	forky, sid	0.0.26-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-multipart	source	(unstable)	(unfixed)

Notes

[trixie] - python-multipart <no-dsa> (Minor issue)
https://github.com/Kludex/python-multipart/security/advisories/GHSA-v9pg-7xvm-68hf
https://github.com/Kludex/python-multipart/pull/297
Fixed by: https://github.com/Kludex/python-multipart/commit/c814948acf509cef7881fa75c969969b19239bbf (0.0.31)