CVE-2026-12644
MEDIUM
NVD
CVSS Score
5.3
Severity
MEDIUM
Published
Jun 19, 2026
Vendor
unknown
Description
Versions of the package ts-deepmerge before 8.0.0 are vulnerable to Uncaught Exception due to the improper handling of built-in Object.prototype methods (such as toString, valueOf). When user-controlled input contains these keys with non-function values, the resulting merged object becomes broken — any string context operation throws a TypeError, crashing the application.