CVE-2025-66648: Vega functions Cross-Site Scripting Vulnerability
HIGHCVE-2025-66648 is a HIGH (CVSS 7.2) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Vega functions libraries in the npm ecosystem. The issue involves `vega-functions` vulnerable to cross-site scripting via `setdata` function. Remediation is available by upgrading affected packages to version 6.1.1.
CVE-2025-66648 at a Glance
Security Impact
CVSS: 7.2
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N).
How to Fix CVE-2025-66648
To remediate this vulnerability, upgrade all affected Vega functions dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install vega-functions@6.1.1Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls vega-functionsHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2025-66648, inspect your project dependencies using npm:
npm ls vega-functionsAnalyze the terminal output to locate any version of Vega functions in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.1.1), your application is affected.
Note: The npm ls vega-functions command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Vega functions, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-66648 Affected Vega functions Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
vega-functions
|
npm |
< 6.1.1
|
6.1.1
|
References
Frequently Asked Questions
What is CVE-2025-66648?
Which Vega functions versions are affected?
What version fixes CVE-2025-66648?
Is vega-functions affected?
What is the CVSS score of CVE-2025-66648?
What CWE is associated with CVE-2025-66648?
How can I check npm dependencies for CVE-2025-66648?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-m9rg-mr6g-75gm",
"modified" : "2026-01-06T15:51:53Z",
"published" : "2026-01-05T22:58:07Z",
"aliases" : [ "CVE-2025-66648" ],
"summary" : "`vega-functions` vulnerable to Cross-site Scripting via `setdata` function",
"details" : "### Impact\n\nFor sites that allow users to supply untrusted user input, malicious use of an internal function (not part of the [public API](https://vega.github.io/vega/docs/expressions/)) could be used to run unintentional javascript (XSS).\n\n### Patches\n\nFixed in vega-functions `6.1.1`\n\n### Workarounds\n\nThere is no workaround besides upgrading. Using `vega.expressionInterpreter` as described in [CSP safe mode](https://vega.github.io/vega/usage/interpreter/) does not prevent this issue. \n\n\n### Exploit Proof of Concept\n\nVega's expression `modify()` [function](https://github.com/vega/vega/blob/d8add5819346e5af597d82ef8253742acc0283ba/packages/vega-functions/src/functions/modify.js#L40), used by setdata, allows attacker to control both the method called and the values supplied, which results to XSS . This was a previous POC:\n\n\n```json\n{\n \"$schema\": \"https://vega.github.io/schema/vega/v6.json\",\n \"data\": [\n {\n \"name\": \"table\",\n \"values\": [\n {\"category\": \"A\", \"amount\": 28}\n ]\n }\n ],\n \"signals\": [\n {\n \"name\": \"tooltip\",\n \"value\": {},\n \"on\": [\n {\"events\": {\"type\":\"timer\",\"throttle\":2000}, \"update\": \"setdata('table',[['Domain: '+event.dataflow._el.ownerDocument.domain+' , cookies: '+ event.dataflow._el.ownerDocument.cookie ]])+warn('XSS is here', modify('table',2,3,null,event.dataflow._el.ownerDocument.defaultView.alert,{'tttt':'yyyy'}) )\"},\n {\"events\": \"rect:pointerout\", \"update\": \"{}\"}\n ]\n }\n ]\n}\n```",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "vega-functions"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "6.1.1"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 6.1.0"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/vega/vega/security/advisories/GHSA-m9rg-mr6g-75gm"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-66648"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/vega/vega"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-01-05T22:58:07Z",
"nvd_published_at" : "2026-01-05T22:15:51Z"
}
}