CVE-2026-33916

Published: Mar 27, 2026 Last Modified: Mar 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 4,7
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: required
Scope: changed
Confidentiality: low
Integrity: low
Availability: none

Description

AI Translation Available

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `resolvePartial()` in the Handlebars runtime resolves partial names via a plain property lookup on `options.partials` without guarding against prototype-chain traversal. When `Object.prototype` has been polluted with a string value whose key matches a partial reference in a template, the polluted string is used as the partial body and rendered without HTML escaping, resulting in reflected or stored XSS. Version 4.7.9 fixes the issue. Some workarounds are available. Apply `Object.freeze(Object.prototype)` early in application startup to prevent prototype pollution. Note: this may break other libraries, and/or use the Handlebars runtime-only build (`handlebars/runtime`), which does not compile templates and reduces the attack surface.

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
0,0003
Percentile
0,1th
Updated

EPSS Score Trend (Last 2 Days)

79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Confidentiality Integrity Availability
Potential Impacts:
Bypass Protection Mechanism Read Application Data Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: AI/ML, Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Incomplete
Abstraction: Variant Structure: Simple
Common Consequences
Security Scopes Affected:
Confidentiality Integrity Availability
Potential Impacts:
Read Application Data Modify Application Data Dos: Crash, Exit, Or Restart
Applicable Platforms
Languages: JavaScript
View CWE Details
https://github.com/handlebars-lang/handlebars.js/commit/68d…
https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084…
https://github.com/handlebars-lang/handlebars.js/releases/t…
https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9
https://github.com/handlebars-lang/handlebars.js/security/a…
https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-2qvq-…