CVE-2019-20920

Name: CVE-2019-20920
Creator: NVD / NIST
Published: 2020-09-30T18:15:17.927+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 3.19%

Last modified Jun 17, 2026

CVE-2019-20920 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. EPSS estimates a 3.19% chance of exploitation in the next 30 days.

Description

Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. This can be used to run arbitrary code on a server processing Handlebars templates or in a victim's browser (effectively serving as XSS).

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L

EPSS Probability

3.19%

86.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-94

Affected Software

Vendor	Product	Versions
Handlebarsjs	Handlebars	< 3.0.8
Handlebarsjs	Handlebars	>= 4.0.0, < 4.5.3

References

https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478Third Party Advisory
https://www.npmjs.com/advisories/1316Exploit, Third Party Advisory
https://www.npmjs.com/advisories/1324Third Party Advisory
https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478Third Party Advisory
https://www.npmjs.com/advisories/1316Exploit, Third Party Advisory
https://www.npmjs.com/advisories/1324Third Party Advisory

Timeline

Published: Sep 30, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-20920?

How severe is CVE-2019-20920?

CVE-2019-20920 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 3.19% probability of exploitation in the next 30 days.

How do I fix CVE-2019-20920?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-20920?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST