{"cve":"CVE-2026-93753","nvd":{"published":"2026-09-18T18:18:34.487","modified":"2026-09-23T17:17:50.017","status":"Deferred","description":"deepmerge through 4.3.1 contains a prototype poisoning vulnerability in the mergeObject() function that fails to properly validate keys being written to target objects. Attackers can supply malicious source objects in merge operations to inject attacker-controlled properties into the returned object's prototype, causing applications to inherit unintended values when accessing properties without own-property checks.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":8.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-1321"],"references":["https://github.com/TehShrike/deepmerge","https://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60","https://github.com/TehShrike/deepmerge/issues/273","https://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject","https://github.com/TehShrike/deepmerge/issues/273"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-93753","score":0.00514,"percentile":0.43823,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-gcqx-w48m-w2h4","url":"https://osv.dev/vulnerability/GHSA-gcqx-w48m-w2h4","summary":"deepmerge mergeObject() allows prototype poisoning of returned objects","modified":"2026-10-27T21:45:04.256048049Z","packages":[{"ecosystem":"npm","name":"deepmerge","purl":"pkg:npm/deepmerge","ranges":[">=4.2.0 <=4.3.1"],"fixed":[]}]}],"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."]}