{"id":"CVE-2026-33939","revision":"93969a71d2824e6d90fef12df13d674a","records":[{"revision":"93969a71d2824e6d90fef12df13d674a","observedAt":"2026-10-25T08:17:29.602+00:00","statement":{"source":"nvd","id":"CVE-2026-33939","aliases":[],"title":"Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. `{{*n}}`), the compiled templat…","description":"Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. `{{*n}}`), the compiled template calls `lookupProperty(decorators, \"n\")`, which returns `undefined`. The runtime then immediately invokes the result as a function, causing an unhandled `TypeError: ... is not a function` that crashes the Node.js process. Any application that compiles user-supplied templates without wrapping the call in a `try/catch` is vulnerable to a single-request Denial of Service. Version 4.7.9 fixes the issue. Some workarounds are available. Wrap compilation and rendering in `try/catch`. Validate template input before passing it to `compile()`; reject templates containing  decorator syntax (`{{*...}}`) if decorators are not used in your application. Use the pre-compilation workflow; compile templates at build time and serve only pre-compiled  templates; do not call `compile()` at request time.","state":0,"publishedAt":"2026-03-27T22:16:20.857+00:00","modifiedAt":"2026-09-04T13:19:26.173+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"},{"system":"CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2","https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9","https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-37pm-9jff","https://access.redhat.com/errata/RHSA-2026:10175","https://access.redhat.com/errata/RHSA-2026:34342","https://access.redhat.com/security/cve/CVE-2026-33939","https://bugzilla.redhat.com/show_bug.cgi?id=2452508","https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33939.json"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33939","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Modified","weaknesses":["CWE-754","CWE-248"],"productCriteria":["cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-03-27T22:16:20.857","lastModified":"2026-09-04T13:19:26.173"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-33939","identifiers":["CVE-2026-33939"]},"retained":false,"historicalAffected":[]}],"coverage":[]}