SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-12644

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).

MEDIUM 5.5EPSS 0.51%

Does this matter?

Lower severity and a low EPSS score (0.51%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0
5.5 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.51% probability · 42th percentile
CISA KEV
Not listed
Weakness
CWE-248
Source
report@snyk.io

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.