# CVE-2023-0410: Builder.io Qwik cross-site scripting in attribute handling

Source: https://junglewise.ai/threats/cve-2023-0410-builder-io-qwik-cross-site-scripting-in-attribute-handling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-01-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2023-0410 · Severity: low · CVSS 3.1 · Published 2023-01-20

@builder.io/qwik is a JavaScript framework for building web applications. The framework failed to properly sanitize attribute names and class attribute values during server-side rendering, allowing attackers to inject malicious scripts that execute in users' browsers. This could lead to theft of session tokens, credentials, or personal data from affected web applications built with vulnerable versions.

Technologies: [@builder.io/qwik (npm)](https://junglewise.ai/threats/technologies/builder-io-qwik). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2023-0410 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-0410 being exploited in the wild.

**How severe is CVE-2023-0410?** Low severity, with a CVSS score of 3.1, published 20 January 2023.

**Which products and versions are affected?** @builder.io/qwik (npm) SEMVER:introduced=0,fixed=0.16.2.

**Is there a fix for CVE-2023-0410?** Yes. @builder.io/qwik (npm): upgrade to 0.16.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2023-0410 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2023-0410?** Check whether you run @builder.io/qwik (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @builder.io/qwik (npm): upgrade to 0.16.2 or later

  ```sh
  npm install @builder.io/qwik@0.16.2
  ```


## Technical details

The vulnerability is a cross-site scripting (XSS) flaw in @builder.io/qwik's server-side rendering (SSR) implementation. The root cause is improper sanitization of HTML attribute names and class attribute values, allowing an attacker to inject arbitrary HTML/JavaScript through these vectors. The attack requires user interaction (UI:R) but is network-reachable and requires no authentication. An attacker can craft a payload that executes JavaScript in the context of the affected web application, potentially stealing cookies, session tokens, or performing actions on behalf of the user. The vulnerability was fixed in version 0.16.2 via commit 4b2f89d, which implements proper cleansing of SSR attribute names and class values.

## Affected products

- Builder.io Qwik before 0.16.2

## Identifiers

- CVE-2023-0410
- GHSA-hm7f-rq7q-j9xp

## Timeline

- 2023-01-20: disclosed
- 2023-01-20: patched: Version 0.16.2 released with fix

## References

- [https://github.com/builderio/qwik/commit/4b2f89dbbd2bc0a2c92eae1a49bdd186e589151a](https://github.com/builderio/qwik/commit/4b2f89dbbd2bc0a2c92eae1a49bdd186e589151a)

## Related threats

- [Qwik server denial of service via malformed Resource thenable](https://junglewise.ai/threats/cve-2026-84994-qwik-crashing-any-qwik-server-via-resource-thenable)
- [Qwik remote code execution via server$ deserialization](https://junglewise.ai/threats/cve-2026-27971-qwik-remote-code-execution-via-server-deserialization)
- [Qwik mutation XSS due to improper HTML escaping in SSR](https://junglewise.ai/threats/cve-2024-41677-qwik-mutation-xss-due-to-improper-html-escaping-in-ssr)
- [BuilderIO Qwik code injection in PureFunctionSerializer](https://junglewise.ai/threats/cve-2023-1283-builderio-qwik-code-injection-in-purefunctionserializer)