{"id":"CVE-2026-12644","aliases":["GHSA-87mf-gv2c-c62c"],"url":"https://o3.security/vulnerability/CVE-2026-12644","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.","published":"2026-06-19T05:00:00.666Z","modified":"2026-08-12T03:51:11.166809129Z","cvss":null,"epss":{"score":0.00507,"percentile":0.41709,"asOf":"2026-09-13"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"ts-deepmerge","fixedVersion":"8.0.0"}],"fix":{"url":"https://github.com/voodoocreation/ts-deepmerge/commit/305a05831a462fb2c353d3cbbff55a0733286f8c","label":"voodoocreation/ts-deepmerge@305a058"},"references":[{"type":"WEB","url":"https://gist.github.com/igorg1312/775fa00114c4d47df6ae0551779ab407"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-JS-TSDEEPMERGE-17339141"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12644.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12644"},{"type":"FIX","url":"https://github.com/voodoocreation/ts-deepmerge/commit/305a05831a462fb2c353d3cbbff55a0733286f8c"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:11.166809129Z"}}