CVE-2019-20920High· 8.1▾ TwilightHandlebars 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…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 44.6 · likelihood 0.6 · exploitation 0
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Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
3.2%
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).
handlebars < 3.0.8handlebars >= 4.0.0, < 4.5.3Upgrade past the affected range:
handlebars 4.5.3Connected by shared product, vendor, weakness, or advisory.
CVE-2026-33940High· 8.1Handlebars provides the power necessary to let users build semantic templates
CVE-2026-33937Critical· 9.8Handlebars provides the power necessary to let users build semantic templates
CVE-2026-33941High· 8.2Handlebars provides the power necessary to let users build semantic templates
CVE-2026-33938High· 8.1Handlebars provides the power necessary to let users build semantic templates
CVE-2021-23383Medium· 5.6The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.
CVE-2021-23369Medium· 5.6The package handlebars before 4.7.7 are vulnerable to Remote Code Execution (RCE) when selecting certain compiling options to compile templates coming from an untrusted source.