{"cve":"CVE-2019-20920","nvd":{"published":"2020-09-30T18:15:17.927","modified":"2026-10-08T22:16:54.603","status":"Modified","description":"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 run arbitrary code on a server processing Handlebars templates or in a victim's browser (effectively serving as XSS).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L","score":8.1},"cwes":["CWE-94"],"references":["https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478","https://www.npmjs.com/advisories/1316","https://www.npmjs.com/advisories/1324","https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478","https://www.npmjs.com/advisories/1316"],"products":["handlebarsjs:handlebars"],"source":"nvd","synced_at":"2026-10-19T21:09:53.489947993+00:00"},"epss":{"cve":"CVE-2019-20920","score":0.03154,"percentile":0.87868,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-3cqr-58rm-57f8","url":"https://osv.dev/vulnerability/GHSA-3cqr-58rm-57f8","summary":"Arbitrary Code Execution in Handlebars","modified":"2026-09-10T03:49:16.886485583Z","packages":[{"ecosystem":"npm","name":"handlebars","purl":"pkg:npm/handlebars","ranges":["<3.0.8"],"fixed":["3.0.8"]},{"ecosystem":"npm","name":"handlebars","purl":"pkg:npm/handlebars","ranges":[">=4.0.0 <4.5.3"],"fixed":["4.5.3"]}]}],"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."]}