# CVE-2026-25150: Prototype Pollution via FormData Processing in Qwik City

> Unauthenticated attackers can pollute Object.prototype via crafted form data in Qwik City, potentially leading to privilege escalation or authentication bypass.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Feb 2026
- **Updated:** 4 Feb 2026
- **Also known as:** GHSA-xqg6-98cw-gxhq

## What is CVE-2026-25150?

CVE-2026-25150 is a critical vulnerability in QwikDev qwik, published on 3 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Qwik is a performance focused javascript framework. Prior to version 1.19.0, a prototype pollution vulnerability exists in the formToObj() function within @builder.io/qwik-city middleware. The function processes form field names with dot notation (e.g., user.name) to create nested objects, but fails to sanitize dangerous property names like __proto__, constructor, and prototype. This allows unauthenticated attackers to pollute Object.prototype by sending crafted HTTP POST requests, potentially leading to privilege escalation, authentication bypass, or denial of service. This issue has been patched in version 1.19.0.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2026-25150?

2 open source packages ship an affected version, including @builder.io/qwik-city. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@builder.io/qwik-city` | npm | All versions | 1.19.0 |
| `@builder.io/qwik-city` | npm | All versions | 1.19.0 |

Products: Qwik Qwik.

## How do I fix CVE-2026-25150?

Upgrade @builder.io/qwik-city to 1.19.0 or later.

## Is CVE-2026-25150 being exploited?

There is no known exploitation of CVE-2026-25150 in the wild and no public exploit code.

## Other vulnerabilities in QwikDev qwik

- [CVE-2023-1283](https://insights.sbomify.com/CVE-2023-1283/): Code Injection in builderio/qwik (critical 10.0)
- [CVE-2026-27971](https://insights.sbomify.com/CVE-2026-27971/): Qwik affected by unauthenticated RCE via server$ Deserialization (critical 9.2)
- [CVE-2026-32701](https://insights.sbomify.com/CVE-2026-32701/): Qwik has array method pollution in FormData processing, allowing type confusion and DoS (high 7.5)
- [CVE-2024-41677](https://insights.sbomify.com/CVE-2024-41677/): Cross-site Scripting (XSS) vulnerability due to improper HTML escaping in qwik (medium 6.3)
- [CVE-2023-0410](https://insights.sbomify.com/CVE-2023-0410/): Cross-site Scripting (XSS) - Generic in builderio/qwik (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25150 and fix it if it is affected.

What it is: CVE-2026-25150 is a critical vulnerability in QwikDev qwik, published on 3 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-25150 in the wild and no public exploit code.

Affected packages and fixed versions:
- @builder.io/qwik-city (npm): affected all versions; fixed in 1.19.0
- @builder.io/qwik-city (npm): affected all versions; fixed in 1.19.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-25150/ (Markdown: https://insights.sbomify.com/CVE-2026-25150/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25150
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25150
- OSV: https://osv.dev/vulnerability/CVE-2026-25150

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25150/
Summaries are generated and may contain mistakes; the official description above is the record.