Vulnerability library
Security checkMarch 30, 2026

Handlebars.js has JavaScript Injection via AST Type Confusion when passing an object as dynamic partial

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High severitynpmhandlebars

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Description

A crafted object placed in the template context can bypass all conditional guards in resolvePartial() and cause invokePartial() to return undefined. The Handlebars runtime then treats the unresolved partial as a source that needs to be compiled, passing the crafted object to env.compile().

Recommendation

Update the handlebars package to the latest compatible version. Followings are version details:

  • Affected version(s): >= 4.0.0, <= 4.7.8
  • Patched version(s): 4.7.9

References

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See something that needs correcting? Let us knowUpdated March 30, 2026