by Kastro
Paper/Archive/CVE-2026-34221

CVE-2026-34221

mikro-orm mikro-orm — MikroORM has Prototype Pollution in Utils.merge

EPSS 0.4%CVSS 9.1
critical.is priorityof 100
34
CVSS 9.1 (NVD)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 32.4.324 × 206.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
mikro-orm< 6.6.10–CNA
mikro-orm>= 7.0.0-rc.0, < 7.0.6–CNA

Scores by source

NVD9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
GitHub_M (CNA)8.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

refgithub.com/mikro-orm/mikro-orm/security/advisories/GHSA-qpfv-44f3-qqx6