HighGHSA-q2c6-c6pm-g3gh

Arbitrary Code Execution in handlebars

Published 4 Sept 2020 · Updated 10 Sept 2026

Affected packages

handlebarsnpm

Affected: <3.0.8
Fixed in: 3.0.8

Update to the fixed version for your release line, for example:npm install handlebars@3.0.8

handlebarsnpm

Affected: >=4.0.0 <4.5.3
Fixed in: 4.5.3

Update to the fixed version for your release line, for example:npm install handlebars@4.5.3

Details

Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It is due to an incomplete fix for a previous issue. This vulnerability can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).

Recommendation

Upgrade to version 3.0.8, 4.5.3 or later.

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References

Linkwww.npmjs.com/advisories/1324

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.