CVE-2016-10547
Cross-Site Scripting in nunjucks
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2016-10547- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2016-10547- Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2018-0746 No score
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.
- Record
EUVD-2018-0746- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f7ph-p5rv-phw2 No score
Cross-Site Scripting in nunjucks
Affected versions of nunjucks do not properly escape specially structured user input in template vars when in auto-escape mode, resulting in a cross-site scripting vulnerability.
Proof of Concept
By using an array for the keys in a template var, escaping is bypassed.
name[]=<script>alert(1)</script>
A full PoC is available in the references section.
Recommendation
Update to version 2.4.3 or later.
- Record
GHSA-f7ph-p5rv-phw2- Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2016-10547- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-f7ph-p5rv-phw2 No score
Cross-Site Scripting in nunjucks
Affected versions of nunjucks do not properly escape specially structured user input in template vars when in auto-escape mode, resulting in a cross-site scripting vulnerability.
Proof of Concept
By using an array for the keys in a template var, escaping is bypassed.
name[]=<script>alert(1)</script>
A full PoC is available in the references section.
Recommendation
Update to version 2.4.3 or later.
- Record
GHSA-f7ph-p5rv-phw2- Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nunjucksnpm |
before 2.4.3 | 2.4.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2016-10547 is a medium vulnerability (CVSS 6.1) in Mozilla Nunjucks, published May 31, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.42%, the 72nd percentile. Fixed in nunjucks 2.4.3.