CVE-2026-93753

Name	CVE-2026-93753
Description	deepmerge through 4.3.1 contains a prototype poisoning vulnerability in the mergeObject() function that fails to properly validate keys being written to target objects. Attackers can supply malicious source objects in merge operations to inject attacker-controlled properties into the returned object's prototype, causing applications to inherit unintended values when accessing properties without own-property checks.
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	1148407

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-deepmerge (PTS)	bookworm	4.2.2+~1.1.1-3	vulnerable
	forky, sid, trixie	4.3.1+~1.1.1-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-deepmerge	source	(unstable)	(unfixed)			1148407

Notes

[trixie] - node-deepmerge <no-dsa> (Minor issue)
[bookworm] - node-deepmerge <postponed> (Minor issue)
https://github.com/TehShrike/deepmerge/issues/273