How severe is CVE-2019-20920?

CVE-2019-20920 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2019-20920 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-20920?

CVE-2019-20920 affects Handlebarsjs Handlebars. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-20920?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-20920 published?

CVE-2019-20920 was published on 2020-09-30 and last updated on 2026-06-17.

CVE-2019-20920

CVE-2019-20920 is a high-severity vulnerability in Handlebarsjs Handlebars with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Handlebarsjs Handlebars
Published: 2020-09-30
Last modified: 2026-06-17

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).

Frequently asked questions

What is CVE-2019-20920?: 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).
How severe is CVE-2019-20920?: CVE-2019-20920 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2019-20920 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-20920?: CVE-2019-20920 affects Handlebarsjs Handlebars. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-20920?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-20920 published?: CVE-2019-20920 was published on 2020-09-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*

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