{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.3.1"
              },
              {
                "fixed": "4.3.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5b87756a5671635679001cbac72aa42f23472c81"
            }
          ],
          "repo": "https://github.com/tehshrike/deepmerge",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-1321"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93753.json"
  },
  "details": "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.",
  "id": "CVE-2026-93753",
  "modified": "2026-09-20T11:31:03.213278278Z",
  "published": "2026-09-18T17:51:37.794Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93753.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93753"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/TehShrike/deepmerge/issues/273"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/TehShrike/deepmerge"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "deepmerge through 4.3.1 Prototype Poisoning via mergeObject"
}