HighGHSA-g9r4-xpmj-mj65
Prototype Pollution 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@3.0.8handlebarsnpm
- 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@4.5.3Details
Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to prototype pollution. It is possible to add or modify properties to the Object prototype through a malicious template. This may allow attackers to crash the application or execute Arbitrary Code in specific conditions.
Recommendation
Upgrade to version 3.0.8, 4.5.3 or later.
Is GHSA-g9r4-xpmj-mj65 in any of your client repos?
Checking one package by hand is fine. Checking it across forty client projects is not. NPMscan reads the lockfiles in every GitHub repo you pick, finds each project with an affected handlebars, and gives you the command that fixes it.
References
Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.