CVE-2026-96748

Name	CVE-2026-96748
Description	PyMongo's connection string parsing decodes percent-encoded characters in the host portion before the host list is separated on its delimiters. When an application places a hostname value supplied by an unauthenticated party into a connection string, that party may cause additional servers of their choosing to be added to the application's database client. The application may then send its authentication exchange and database operations to one of those servers, which can observe limited information and return altered results.
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)
Debian Bugs	1148967

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pymongo (PTS)	bookworm	3.11.0-1+deb12u1	vulnerable
	trixie	4.10.1-6	vulnerable
	forky, sid	4.18.2-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
pymongo	source	(unstable)	4.18.2-1			1148967

Notes

[trixie] - pymongo <no-dsa> (Minor issue)
[bookworm] - pymongo <postponed> (Minor issue)
https://github.com/mongodb/mongo-python-driver/security/advisories/GHSA-vp6j-j7w5-5xjj