{"id":"EUVD-2026-83258","enisaUuid":"db85f91b-8d09-395b-850f-c1e9d84e833e","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\u0027s prototype, causing applications to inherit unintended values when accessing properties without own-property checks.","datePublished":"Sep 18, 2026, 5:51:37 PM","dateUpdated":"Sep 24, 2026, 2:23:12 PM","baseScore":8.7,"baseScoreVersion":"4.0","baseScoreVector":"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","references":"https://github.com/TehShrike/deepmerge/issues/273\nhttps://github.com/TehShrike/deepmerge\nhttps://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60\nhttps://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject\n","aliases":"CVE-2026-93753\nGHSA-gcqx-w48m-w2h4\n","assigner":"VulnCheck","epss":0.51,"enisaIdProduct":[{"id":"f726ab09-88d7-3f1e-aaa7-9f2aaa33cca3","product":{"name":"deepmerge","vendor":{"name":"TehShrike"}},"product_version":"0 ≤4.3.1"}],"enisaIdVendor":[{"id":"ebff23b3-8676-3c48-9de3-72c992ac9431","vendor":{"name":"TehShrike"}}],"enisaIdVulnerability":[{"id":"08aec393-d94b-31b8-aff9-bb1c970e1131","vulnerability":{"id":"GHSA-gcqx-w48m-w2h4","description":"deepmerge mergeObject() allows prototype poisoning of returned objects","datePublished":"Sep 18, 2026, 6:31:44 PM","dateUpdated":"Oct 27, 2026, 9:34:55 PM","baseScore":0.0,"references":"https://nvd.nist.gov/vuln/detail/CVE-2026-93753\nhttps://github.com/TehShrike/deepmerge/issues/273\nhttps://github.com/TehShrike/deepmerge\nhttps://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60\nhttps://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject\n","enisa_id":"EUVD-2026-83258\n","aliases":"CVE-2026-93753\nGHSA-gcqx-w48m-w2h4\n","epss":0.0,"dataProcessed":"Oct 28, 2026, 12:01:16 PM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}},{"id":"440081b4-253e-34e2-ad41-1d2ac938da1c","vulnerability":{"id":"CVE-2026-93753","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\u0027s prototype, causing applications to inherit unintended values when accessing properties without own-property checks.","datePublished":"Sep 18, 2026, 5:51:37 PM","dateUpdated":"Sep 24, 2026, 2:23:12 PM","status":"PUBLISHED","baseScore":8.7,"baseScoreVersion":"4.0","baseScoreVector":"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","references":"https://github.com/TehShrike/deepmerge/issues/273\nhttps://github.com/TehShrike/deepmerge\nhttps://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60\nhttps://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject\n","enisa_id":"EUVD-2026-83258\n","assigner":"VulnCheck","epss":0.51,"dataProcessed":"Oct 28, 2026, 7:19:41 AM","vulnerabilityProduct":[{"id":"48a8562a-3d7a-31a0-8c87-8ac144a82103","product":{"name":"deepmerge","vendor":{"name":"TehShrike"}},"product_version":"0 ≤4.3.1"}],"vulnerabilityVendor":[{"id":"75bdcd8c-dce0-3f54-a9f5-4c1e2ad71113","vendor":{"name":"TehShrike"}}]}}],"enisaIdAdvisory":[]}