Sign in
Deutsch English Español Polski
Critical

Remote code execution in handlebars when compiling templates

  • Disclosed: 06.05.2021
  • Updated: 11.10.2026 13:19

The package handlebars before 4.7.7 are vulnerable to Remote Code Execution (RCE) when selecting certain compiling options to compile templates coming from an untrusted source.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.webjars.bowergithub.wycats:handlebars.js < 4.7.7 4.7.7
Java / Kotlin (Maven) org.webjars:handlebars < 4.7.7 4.7.7
Java / Kotlin (Maven) org.webjars.npm:handlebars < 4.7.7 4.7.7
npm package handlebars < 4.7.7 4.7.7

References

CVSS score 9.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-94
Platform
Java / Kotlin (Maven), npm
Package
org.webjars.bowergithub.wycats:handlebars.js, org.webjars:handlebars, org.webjars.npm:handlebars
Disclosed
06.05.2021
Updated
11.10.2026 13:19

Sources and licenses

OSV / GitHub Advisory Database - GHSA-f2jv-r9rf-7988 - CC BY 4.0

Vulnerability history: handlebars

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (22) in the archive
Total entries
22
First → latest
10.2018 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 6
  • High 10
  • Medium 5
  • Low 1

Disclosures per year

Severity:
  1. Handlebars: JavaScript Injection via AST Type Confusion in compile (bypass of CVE-2026-33937)
    Critical · 9.8 CVE-2026-106446 >= 4.0.0, < 4.7.10 4.7.10
  2. Handlebars: JavaScript Injection via Own Property Check Bypass
    Critical CVE-2026-106445 >= 3.0.0, < 4.7.10 4.7.10
  3. Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options
    High · 8.2 CVE-2026-33941 >= 4.0.0, < 4.7.9 4.7.9
  4. Handlebars.js has JavaScript Injection via AST Type Confusion when passing an object as dynamic partial
    High · 8.1 CVE-2026-33940 >= 4.0.0, < 4.7.9 4.7.9
  5. Handlebars.js has Denial of Service via Malformed Decorator Syntax in Template Compilation
    High · 7.5 CVE-2026-33939 >= 4.0.0, < 4.7.9 4.7.9
  6. Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block
    High · 8.1 CVE-2026-33938 >= 4.0.0, < 4.7.9 4.7.9
  7. Handlebars.js has JavaScript Injection via AST Type Confusion
    Critical · 9.8 CVE-2026-33937 >= 4.0.0, < 4.7.9 4.7.9
  8. Prototype Pollution in handlebars
    Critical · 9.8 CVE-2021-23383 < 4.7.7 4.7.7
  9. Regular Expression Denial of Service in Handlebars
    High · 7.5 CVE-2019-20922 >= 4.0.0, < 4.4.5 4.4.5
  10. Arbitrary Code Execution in Handlebars
    High · 8.1 CVE-2019-20920 < 3.0.8, >= 4.0.0, < 4.5.3 3.0.8, 4.5.3
  11. Remote code execution in handlebars when compiling templates this entry
    Critical · 9.8 CVE-2021-23369 < 4.7.7 4.7.7
  12. Arbitrary Code Execution in handlebars
    High ghsa-q2c6-c6pm-g3gh < 3.0.8, >= 4.0.0, < 4.5.3 3.0.8, 4.5.3
  13. Prototype Pollution in handlebars
    High ghsa-g9r4-xpmj-mj65 < 3.0.8, >= 4.0.0, < 4.5.3 3.0.8, 4.5.3
  14. Arbitrary Code Execution in handlebars
    High · 7.3 ghsa-2cf5-4w76-r9qv < 3.0.8, >= 4.0.0, < 4.5.2 3.0.8, 4.5.2
  15. Prototype Pollution in handlebars
    Critical · 9.8 CVE-2019-19919 >= 4.0.0, < 4.3.0, < 3.0.8 4.3.0, 3.0.8
  16. Prototype Pollution in handlebars
    High · 7.3 ghsa-q42p-pg8m-cqh6 >= 4.1.0, < 4.1.2, >= 4.0.0, < 4.0.14, < 3.0.7 4.1.2, 4.0.14, 3.0.7

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Privacy policy

Free to subscribe. Unsubscribe with one click in any email.