Cross-site Scripting (XSS) Affecting prism package, versions <5.14.3-r13


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-PRISM-15878800
  • published3 Apr 2026
  • disclosed27 Mar 2026

Introduced: 27 Mar 2026

NewCVE-2026-33941  (opens in a new tab)
CWE-79  (opens in a new tab)
CWE-94  (opens in a new tab)
CWE-116  (opens in a new tab)

How to fix?

Upgrade Chainguard prism to version 5.14.3-r13 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream prism package and not the prism package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (bin/handlebars / lib/precompiler.js) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (&#34;, &#39;, ;, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write access to sensitive paths) to limit the impact of successful exploitation. Fourth, audit template filenames in any repository or package that is consumed by an automated build pipeline.

CVSS Base Scores

version 3.1