CVE-2026-25148: @builder.io/qwik city Cross-Site Scripting Vulnerability
MODERATECVE-2026-25148 is a MODERATE cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting @builder.io/qwik city libraries in the npm ecosystem. The issue involves qwik ssr xss via unsafe virtual node serialization. Remediation is available by upgrading affected packages to version 1.19.0.
CVE-2026-25148 at a Glance
How to Fix CVE-2026-25148
To remediate this vulnerability, upgrade all affected @builder.io/qwik city 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 @builder.io/qwik-city@1.19.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls @builder.io/qwik-cityHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-25148, inspect your project dependencies using npm:
npm ls @builder.io/qwik-cityAnalyze the terminal output to locate any version of @builder.io/qwik city in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.19.0), your application is affected.
Note: The npm ls @builder.io/qwik-city 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 @builder.io/qwik city, 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-2026-25148 Affected @builder.io/qwik city Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
@builder.io/qwik-city
|
npm |
< 1.19.0
|
1.19.0
|
References
Frequently Asked Questions
What is CVE-2026-25148?
Which @builder.io/qwik city versions are affected?
What version fixes CVE-2026-25148?
Is @builder.io/qwik-city affected?
What CWE is associated with CVE-2026-25148?
How can I check npm dependencies for CVE-2026-25148?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-m6jq-g7gq-5w3c",
"modified" : "2026-02-04T17:45:39Z",
"published" : "2026-02-03T20:47:55Z",
"aliases" : [ "CVE-2026-25148" ],
"summary" : "Qwik SSR XSS via Unsafe Virtual Node Serialization",
"details" : "### Summary\n\n**Description**\nA Cross-site Scripting (CWE-79) vulnerability in Qwik.js' server-side rendering virtual attribute serialization allows a remote attacker to inject arbitrary web scripts into server-rendered pages via virtual attributes. Successful exploitation permits script execution in a victim's browser in the context of the affected origin. This affects qwik-city before version 1.19.0. This has been patched in qwik-city version 1.19.0.\n\n### Impact\nThis vulnerability impacts applications that dynamically populate Virtual Node attributes with keys/values that users can influence. Applications that hard-code these keys/values are unaffected.\n\nQwik doesn't use traditional hydration. Instead, it serializes application state into the HTML so the client can resume execution from the server-rendered output. To support this, Qwik v1 marks component boundaries with HTML comments. SSR builds comment content for Virtual components by concatenating structural attribute names and values without any escaping or quoting. An attacker-controlled key or value can prematurely close the HTML comment and inject arbitrary HTML/JS.\n\nSuccessful exploitation permits script execution in a victim’s browser in the context of the affected origin. Additionally, because Qwik uses these serialized comment markers for resumability, breaking comment structure can lead to resume/hydration desync and unexpected client-side behavior.\n\n### Patches\nThis has been patched in qwik-city version 1.19.0. Users are strongly encouraged to update to the latest available release.",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "@builder.io/qwik-city"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.19.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/QwikDev/qwik/security/advisories/GHSA-m6jq-g7gq-5w3c"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25148"
}, {
"type" : "WEB",
"url" : "https://github.com/QwikDev/qwik/commit/fe2d9232c0bcec99411d51a00dae29295871d094"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/QwikDev/qwik"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-02-03T20:47:55Z",
"nvd_published_at" : "2026-02-03T22:16:30Z"
}
}