CVE-2026-40345

Published Aug 20, 2026

Last updated 3 days ago

Overview

Description
deepmerge-ts is a typescript library providing functionality to deep merging of javascript objects. Prior to 8.0.0, the deepmerge, deepmergeCustom, deepmergeInto, and deepmergeIntoCustom APIs do not track visited objects or object pairs when recursively merging records. When two input values contain self-references at the same property path, the merge logic repeatedly revisits the same pair until Node.js raises RangeError: Maximum call stack size exceeded. Applications that merge attacker-controlled recursive object graphs can synchronously crash the affected process or cause repeated worker restarts. Plain JSON input alone cannot create the recursive graph required to trigger the issue. This issue is fixed in version 8.0.0.
Source
security-advisories@github.com
NVD status
Received

Risk scores

CVSS 4.0

Type
Secondary
Base score
8.2
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
HIGH

Weaknesses

security-advisories@github.com
CWE-674

Social media

Hype score
Not currently trending