CVE-2019-20920

Exp

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).

Published: 2020-09-30 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-20920 is rated High Exploit Risk (67.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.34%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2019-20920

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-20920

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-03 0.37% 0.34% -0.02%
2 2026-03-04 0.57% 0.37% -0.20%
3 2026-03-01 — 0.57% —

Full EPSS history (34 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-20920

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 5.3 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2019-20920

GitHub Security Advisory for CVE-2019-20920

GHSA-3cqr-58rm-57f8 · Severity: high · Ecosystem: npm — Arbitrary Code Execution in Handlebars

OS Trackers for CVE-2019-20920

vendor priority summary link
debian not yet assigned CVE-2019-20920 not yet assigned priority: Debian including 1 source packages (node-handlebars), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-20920
redhat medium — https://access.redhat.com/security/cve/CVE-2019-20920
ubuntu medium CVE-2019-20920 medium priority: Ubuntu including 2 source packages (libjs-handlebars, node-handlebars), 32 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 17, not-affected 12, needs-triage 2, released 1. https://ubuntu.com/security/CVE-2019-20920

Affected software / configurations for CVE-2019-20920

Vendor Product Version Raw CPE
handlebarsjs handlebars < 3.0.8 cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*
handlebarsjs handlebars >= 4.0.0, < 4.5.3 cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*

References for CVE-2019-20920

URL Tags
https://snyk.io/vuln/SNYK-JS-HANDLEBARS-534478 Third Party Advisory
https://www.npmjs.com/advisories/1316 Exploit Third Party Advisory
https://www.npmjs.com/advisories/1324 Third Party Advisory
cvelogic Threat Intelligence