CVE-2016-10547
MEDIUMCVE-2016-10547 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in nunjucks. 3 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2016-10547 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-Site Scripting in nunjucks
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
nunjucksnpmDescription
Nunjucks is a full featured templating engine for JavaScript. Versions 2.4.2 and lower have a cross site scripting (XSS) vulnerability in autoescape mode. In autoescape mode, all template vars should automatically be escaped. By using an array for the keys, such as name[]=<script>alert(1)</script>, it is possible to bypass autoescaping and inject content into the DOM.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | nunjucks | all versions | 2.4.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nunjucks. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nunjucks to 2.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10547 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.
How O3 protects you
O3 pinpoints whether CVE-2016-10547 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2016-10547. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2016-10547 in your dependencies?
O3 detects CVE-2016-10547 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.