{"cve":"CVE-2026-34221","nvd":{"published":"2026-03-31T16:16:32.293","modified":"2026-07-24T20:10:00.147","status":"Analyzed","description":"MikroORM is a TypeScript ORM for Node.js based on Data Mapper, Unit of Work and Identity Map patterns. Prior to versions 6.6.10 and 7.0.6, a prototype pollution vulnerability exists in the Utils.merge helper used internally by MikroORM when merging object structures. The function did not prevent special keys such as __proto__, constructor, or prototype, allowing attacker-controlled input to modify the JavaScript object prototype when merged. This issue has been patched in versions 6.6.10 and 7.0.6.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L","score":8.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","score":9.1},"cwes":["CWE-1321"],"references":["https://github.com/mikro-orm/mikro-orm/security/advisories/GHSA-qpfv-44f3-qqx6"],"products":["mikro-orm:mikroorm"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-34221","score":0.00383,"percentile":0.32359,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-qpfv-44f3-qqx6","url":"https://osv.dev/vulnerability/GHSA-qpfv-44f3-qqx6","summary":"MikroORM has Prototype Pollution in Utils.merge","modified":"2026-03-31T19:04:39.043387Z","packages":[{"ecosystem":"npm","name":"@mikro-orm/core","purl":"pkg:npm/%40mikro-orm/core","ranges":["<6.6.10"],"fixed":["6.6.10"]},{"ecosystem":"npm","name":"@mikro-orm/core","purl":"pkg:npm/%40mikro-orm/core","ranges":[">=7.0.0-dev.0 <7.0.6"],"fixed":["7.0.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}