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.
References
Configurations
History
02 Jul 2026, 12:17
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30 Jun 2026, 03:18
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| CWE | CWE-248 |
31 Mar 2026, 17:50
| Type | Values Removed | Values Added |
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| First Time |
Handlebarsjs
Handlebarsjs handlebars |
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| CPE | cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:* | |
| References | () https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2 - Patch | |
| References | () https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9 - Release Notes | |
| References | () https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-37pm-9jff - Exploit, Vendor Advisory |
30 Mar 2026, 19:16
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| References | () https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-37pm-9jff - |
27 Mar 2026, 22:16
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| New CVE |
Information
Published : 2026-03-27 22:16
Updated : 2026-07-15 02:20
NVD link : CVE-2026-33939
Mitre link : CVE-2026-33939
CVE.ORG link : CVE-2026-33939
JSON object : View
Products Affected
handlebarsjs
- handlebars
