{
"id": "GHSA-87mf-gv2c-c62c",
"aliases": [
"CVE-2026-12644"
],
"details": "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.",
"summary": "ts-deepmerge: Prototype Method Override leads to DoS",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "8.0.0"
}
]
}
],
"package": {
"name": "ts-deepmerge",
"ecosystem": "npm"
}
}
],
"modified": "2026-06-19T21:41:52Z",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V4",
"score": "CVSS: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"
}
],
"published": "2026-06-19T06:31:56Z",
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12644",
"type": "ADVISORY"
},
{
"url": "https://github.com/voodoocreation/ts-deepmerge/commit/305a05831a462fb2c353d3cbbff55a0733286f8c",
"type": "WEB"
},
{
"url": "https://gist.github.com/igorg1312/775fa00114c4d47df6ae0551779ab407",
"type": "WEB"
},
{
"url": "https://github.com/voodoocreation/ts-deepmerge",
"type": "PACKAGE"
},
{
"url": "https://security.snyk.io/vuln/SNYK-JS-TSDEEPMERGE-17339141",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-248"
],
"severity": "MODERATE",
"github_reviewed": true,
"nvd_published_at": "2026-06-19T06:17:01Z",
"github_reviewed_at": "2026-06-19T21:41:52Z"
}
}