{"id":"CVE-2026-93753","title":"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","summary":"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…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","cwe":["CWE-1321"],"vendor":"TehShrike","product":"deepmerge","affected":["deepmerge <= 4.3.1"],"published":"2026-09-18","updated":"2026-09-18","sourceUpdated":"2026-09-18T20:17:33.767","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93753","references":[{"url":"https://github.com/TehShrike/deepmerge","label":"disclosure@vulncheck.com"},{"url":"https://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index.js#L39-L60","label":"disclosure@vulncheck.com"},{"url":"https://github.com/TehShrike/deepmerge/issues/273","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-mergeobject","label":"disclosure@vulncheck.com"},{"url":"https://github.com/TehShrike/deepmerge/issues/273","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-18T19:16:56.102337Z"},"ingestedAt":"2026-09-18T18:47:53.270Z","epss":0.00361,"epssPercentile":0.29858,"slug":"CVE-2026-93753","body":"## Overview\n\ndeepmerge 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":207480,"id":"CVE-2026-93753","ts":1789761069589,"field":"exploit_available","old":"false","new":"true"}]}