CVE-2026-33939

Published: Mar 27, 2026 Last Modified: Mar 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,5
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high

Description

AI Translation Available

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. `{{*n}}`), the compiled template calls `lookupProperty(decorators, 'n')`, which returns `undefined`. The runtime then immediately invokes the result as a function, causing an unhandled `TypeError: ... is not a function` that crashes the Node.js process. Any application that compiles user-supplied templates without wrapping the call in a `try/catch` is vulnerable to a single-request Denial of Service. Version 4.7.9 fixes the issue. Some workarounds are available. Wrap compilation and rendering in `try/catch`. Validate template input before passing it to `compile()`; reject templates containing decorator syntax (`{{*...}}`) if decorators are not used in your application. Use the pre-compilation workflow; compile templates at build time and serve only pre-compiled templates; do not call `compile()` at request time.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0004
Percentile
0,1th
Updated

EPSS Score Trend (Last 2 Days)

754

Improper Check for Unusual or Exceptional Conditions

Incomplete
Common Consequences
Security Scopes Affected:
Integrity Availability
Potential Impacts:
Dos: Crash, Exit, Or Restart Unexpected State
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084…
https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9
https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-…