cvedb.io
CVE-2026-33939
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-03-27T22:16:20.857 · Last modified 2026-07-02T12:17:08.880

Summary

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 co

Affected products

handlebarsjs — handlebars

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.