CVE-2021-32819

Remote code execution in squirrelly

8.0 HighPublic exploitFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

58.3%Up 56.9 points since May 15, 2021

What each source reports

CVE List Score used 8.0

Remote code execution in squirrelly

Record: CVE-2021-32819
CVSS 3.1: 8.0 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
Weakness: CWE-200
Updated: 2026-11-02

EUVDEUVD-2021-1163 8.0

Record: EUVD-2021-1163
CVSS 3.1: 8.0 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
Updated: 2026-11-03

GitHub AdvisoriesGHSA-q8j6-pwqx-pm96 8.0

Insecure template handling in Squirrelly

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. Version 9.0.0 has a fix for this issue. For complete details refer to the referenced GHSL-2021-023.

Record: GHSA-q8j6-pwqx-pm96
CVSS 3.1: 8.0 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
Weakness: CWE-200
Updated: 2026-11-02

NVD 8.0

Record: CVE-2021-32819
CVSS 3.1: 8.0 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0: 6.8 MediumAV:N/AC:M/Au:N/C:P/I:P/A:P
Weakness: CWE-200
Updated: 2026-11-02

OSV 8.8

Record: CVE-2021-32819
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVGHSA-q8j6-pwqx-pm96 8.0

Insecure template handling in Squirrelly

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. Version 9.0.0 has a fix for this issue. For complete details refer to the referenced GHSL-2021-023.

Record: GHSA-q8j6-pwqx-pm96
CVSS 3.1: 8.0 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
Weakness: CWE-200
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`squirrelly` npm	through 8.0.8	9.0.0
`squirrelly` npm	before 9.0.0	9.0.0

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Nuclei	Nodejs Squirrelly - Remote Code Execution
PoC in GitHub	Abady0x1/CVE-2021-32819	2021-06-12

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, Nuclei, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-32819 is a high vulnerability (CVSS 8.0) in Squirrelly, published May 14, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 58.3%, the 99th percentile. Fixed in squirrelly 9.0.0.