{"id":"GHSA-87mf-gv2c-c62c","summary":"ts-deepmerge: Prototype Method Override leads to DoS","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.","aliases":["CVE-2026-12644"],"modified":"2026-06-19T21:56:30.084657Z","published":"2026-06-19T06:31:56Z","database_specific":{"cwe_ids":["CWE-248"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-06-19T21:41:52Z","nvd_published_at":"2026-06-19T06:17:01Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12644"},{"type":"WEB","url":"https://github.com/voodoocreation/ts-deepmerge/commit/305a05831a462fb2c353d3cbbff55a0733286f8c"},{"type":"WEB","url":"https://gist.github.com/igorg1312/775fa00114c4d47df6ae0551779ab407"},{"type":"PACKAGE","url":"https://github.com/voodoocreation/ts-deepmerge"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-JS-TSDEEPMERGE-17339141"}],"affected":[{"package":{"name":"ts-deepmerge","ecosystem":"npm","purl":"pkg:npm/ts-deepmerge"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.0.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-87mf-gv2c-c62c/GHSA-87mf-gv2c-c62c.json"}}],"schema_version":"1.9.0","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"}]}