How severe is CVE-2016-3942?

CVE-2016-3942 has a CVSS score of 6.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2016-3942?

CVE-2016-3942 affects the following packages: jsrender (npm). Ecosystems affected: npm.

How do I fix CVE-2016-3942?

Update jsrender to 0.9.74 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-3942 is resolved across your whole dependency graph.

How do I detect CVE-2016-3942 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsrender, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2016-3942 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2016-3942 actively exploited in the wild?

No public exploit code has been indexed for CVE-2016-3942 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2016-3942 published, and has it been updated?

CVE-2016-3942 was published on September 1, 2020 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2016-3942 — jsrender

MEDIUMFix: BorisMoore/jsrender@f984e13

CVE-2016-3942 is a medium-severity (CVSS 6.3) remote code execution vulnerability in jsrender. A fix is available for jsrender — see the affected versions and patch details below.

Template Injection in jsrender

Published

Sep 1, 2020

Updated

Nov 8, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2023 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

📦jsrender

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

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 Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`jsrender`	all versions	0.9.74`npm install jsrender@0.9.74`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsrender, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jsrender to 0.9.74 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-3942 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

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

O3 Security · Impact-Aware SCA

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