{"id":"CVE-2019-20920","title":"Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution","summary":"Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. This can be used to…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L","cwe":["CWE-94"],"vendor":"handlebarsjs","product":"handlebars","affected":["handlebars < 3.0.8","handlebars >= 4.0.0, < 4.5.3"],"patched":["handlebars 4.5.3"],"published":"2020-09-30","updated":"2026-10-08","sourceUpdated":"2026-10-08T22:16:54.603","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2019-20920","references":[{"url":"https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478","label":"cve@mitre.org"},{"url":"https://www.npmjs.com/advisories/1316","label":"cve@mitre.org"},{"url":"https://www.npmjs.com/advisories/1324","label":"cve@mitre.org"},{"url":"https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.npmjs.com/advisories/1316","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.npmjs.com/advisories/1324","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.03193,"epssPercentile":0.87727,"ingestedAt":"2026-10-08T23:16:47.308Z","slug":"CVE-2019-20920","body":"## Overview\n\nHandlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. This can be used to run arbitrary code on a server processing Handlebars templates or in a victim's browser (effectively serving as XSS).\n\n## Affected\n\n- `handlebars < 3.0.8`\n- `handlebars >= 4.0.0, < 4.5.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `handlebars 4.5.3`","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.6,"exploitation":0,"ransomware":0},"changes":[]}