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Vulnerability · Published May 4, 2021 · Assigned by snyk

CVE-2021-23383Prototype Pollution

Medium 5.6

In plain English

A medium-severity security flaw in handlebars. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 4.5% (higher than 92% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.6Medium
Exploit odds (30 days)4.5%top 8.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC

Official description

The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12node-handlebars3:4.7.6+~4.1.0-2DEBIAN-CVE-2021-23383
Debian:13node-handlebars3:4.7.6+~4.1.0-2DEBIAN-CVE-2021-23383
Debian:14node-handlebars3:4.7.6+~4.1.0-2DEBIAN-CVE-2021-23383
Ubuntu:22.04:LTSnode-handlebarsno fix listedUBUNTU-CVE-2021-23383
Ubuntu:24.04:LTSnode-handlebarsno fix listedUBUNTU-CVE-2021-23383
Ubuntu:25.10node-handlebarsno fix listedUBUNTU-CVE-2021-23383
Ubuntu:26.04:LTSnode-handlebarsno fix listedUBUNTU-CVE-2021-23383
Ubuntu:26.10node-handlebarsno fix listedUBUNTU-CVE-2021-23383
npmhandlebars4.7.7GHSA-765h-qjxv-5f44

Affected products (as reported)

VendorProductVersions
n/a handlebars unspecified – before 4.7.7

References