UBUNTU-CVE-2026-33938

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Source
https://ubuntu.com/security/CVE-2026-33938
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-33938
Upstream
Published
2026-03-27T21:17:00Z
Modified
2026-04-02T17:31:27Z
Severity
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the @partial-block special variable is stored in the template data context and is reachable and mutable from within a template via helpers that accept arbitrary objects. When a helper overwrites @partial-block with a crafted Handlebars AST, a subsequent invocation of {{> @partial-block}} compiles and executes that AST, enabling arbitrary JavaScript execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (require('handlebars/runtime')). The compile() method is absent, eliminating the vulnerable fallback path. Second, audit registered helpers for any that write arbitrary values to context objects. Helpers should treat context data as read-only. Third, avoid registering helpers from third-party packages (such as handlebars-helpers) in contexts where templates or context data can be influenced by untrusted input.

References

Affected packages

Ubuntu:18.04:LTS / node-handlebars

Package

Name
node-handlebars
Purl
pkg:deb/ubuntu/node-handlebars@3:4.0.10-5?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

3:4.*
3:4.0.10-5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3:4.0.10-5",
            "binary_name": "handlebars"
        },
        {
            "binary_version": "3:4.0.10-5",
            "binary_name": "libjs-handlebars"
        },
        {
            "binary_version": "3:4.0.10-5",
            "binary_name": "libjs-handlebars.runtime"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json"

Ubuntu:20.04:LTS / node-handlebars

Package

Name
node-handlebars
Purl
pkg:deb/ubuntu/node-handlebars@3:4.7.2-1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

3:4.*
3:4.1.0-1
3:4.5.3-1
3:4.7.2-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3:4.7.2-1",
            "binary_name": "handlebars"
        },
        {
            "binary_version": "3:4.7.2-1",
            "binary_name": "libjs-handlebars"
        },
        {
            "binary_version": "3:4.7.2-1",
            "binary_name": "libjs-handlebars.runtime"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json"

Ubuntu:22.04:LTS / node-handlebars

Package

Name
node-handlebars
Purl
pkg:deb/ubuntu/node-handlebars@3:4.7.7+~4.1.0-1?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

3:4.*
3:4.7.6+~4.1.0-2
3:4.7.7+~4.1.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars.runtime"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json"

Ubuntu:24.04:LTS / node-handlebars

Package

Name
node-handlebars
Purl
pkg:deb/ubuntu/node-handlebars@3:4.7.7+~4.1.0-1?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

3:4.*
3:4.7.7+~4.1.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars.runtime"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json"

Ubuntu:25.10 / node-handlebars

Package

Name
node-handlebars
Purl
pkg:deb/ubuntu/node-handlebars@3:4.7.7+~4.1.0-1?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

3:4.*
3:4.7.7+~4.1.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars"
        },
        {
            "binary_version": "3:4.7.7+~4.1.0-1",
            "binary_name": "libjs-handlebars.runtime"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33938.json"