What’s Vulnerable › Vulnerabilities

CVE-2021-32819: Remote code execution in squirrelly

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 58.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-05-14 · updated 2026-06-17
• Weakness: CWE-200

Description

Squirrelly is a template engine implemented in JavaScript that works out of the box with ExpressJS. Squirrelly mixes pure template data with engine configuration options through the Express render API. By overwriting internal configuration options remote code execution may be triggered in downstream applications. This issue is fixed in version 9.0.0. For complete details refer to the referenced GHSL-2021-023.

Affected products

• squirrellyjs squirrelly: 8.0.8

References

• https://github.com/squirrellyjs/squirrelly/commit/c12418a026f73df645ba927fd29358efe02fed1e
• https://github.com/squirrellyjs/squirrelly/commit/dca7a1e7ee91d8a6ffffb655f3f15647486db9da
• https://github.com/squirrellyjs/squirrelly/pull/254
• https://securitylab.github.com/advisories/GHSL-2021-023-squirrelly/
• https://github.com/squirrellyjs/squirrelly/commit/c12418a026f73df645ba927fd29358efe02fed1e
• https://github.com/squirrellyjs/squirrelly/commit/dca7a1e7ee91d8a6ffffb655f3f15647486db9da
• https://github.com/squirrellyjs/squirrelly/pull/254
• https://securitylab.github.com/advisories/GHSL-2021-023-squirrelly/

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