CVE-2026-33938

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Source
https://cve.org/CVERecord?id=CVE-2026-33938
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33938.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-33938
Aliases
Downstream
CGA (121)
CLEANSTART (4)
CLSA (3)
DEBIAN (1)
MINI (14)
ROOT (1)
UBUNTU (1)
Published
2026-03-27T21:05:42Z
Modified
2026-10-20T12:05:57Z
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
Summary
Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block
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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-843",
        "CWE-94"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33938.json"
}
References

Affected packages

Git / github.com/handlebars-lang/handlebars.js

Affected ranges

Type
GIT
Repo
https://github.com/handlebars-lang/handlebars.js
Events
Introduced
bff5fab8f9d42e21950be00dcf1cedf4dc1a565b
Fixed
dce542c9a660048d31f0981ac8a45c08b919bddb
Fixed
68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*",
            "range":  [
                {
                    "introduced":  "4.0.0"
                },
                {
                    "fixed":  "4.7.9"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v4.7.9",
            "range":  [
                {
                    "fixed":  "dce542c9a660048d31f0981ac8a45c08b919bddb"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

v4.*
v4.0.0
v4.0.1
v4.0.10
v4.0.11
v4.0.12
v4.0.2
v4.0.3
v4.0.4
v4.0.5
v4.0.6
v4.0.7
v4.0.8
v4.0.9
v4.1.1
v4.1.2
v4.1.2-0
v4.2.0
v4.2.1
v4.3.0
v4.3.1
v4.3.2
v4.3.3
v4.3.4
v4.4.0
v4.4.1
v4.4.2
v4.4.3
v4.5.0
v4.5.1
v4.5.2
v4.5.3
v4.6.0
v4.7.0
v4.7.1
v4.7.2
v4.7.3
v4.7.4
v4.7.5
v4.7.6
v4.7.7
v4.7.8

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33938.json"