# CVE-2025-47946: Symfony UX allows unsanitized HTML attribute injection via ComponentAttributes

> Attackers can inject malicious HTML attributes leading to XSS when rendering untrusted user input via Symfony UX component attributes.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 19 May 2025
- **Updated:** 20 May 2025
- **Also known as:** GHSA-5j3w-5pcr-f8hg

## What is CVE-2025-47946?

CVE-2025-47946 is a medium-severity cross-site scripting vulnerability in symfony ux, published on 19 May 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Symfony UX is an initiative and set of libraries to integrate JavaScript tools into applications. Prior to version 2.25.1, rendering `{{ attributes }}` or using any method that returns a `ComponentAttributes` instance (e.g. `only()`, `defaults()`, `without()`) ouputs attribute values directly without escaping. If these values are unsafe (e.g. contain user input), this can lead to HTML attribute injection and XSS vulnerabilities. The issue is fixed in version `2.25.1` of `symfony/ux-twig-component` Those who use `symfony/ux-live-component` must also update it to `2.25.1` to benefit from the fix, as it reuses the `ComponentAttributes` class internally. As a workaround, avoid rendering `{{ attributes }}` or derived objects directly if it may contain untrusted values.
Instead, use `{{ attributes.render('name') }}` for safe output of individual attributes.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-47946?

4 open source packages ship an affected version, including symfony/ux-live-component and symfony/ux-twig-component.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `symfony/ux-live-component` | Packagist | All versions | 2.25.1 |
| `symfony/ux-live-component` | Packagist | All versions | 2.25.1 |
| `symfony/ux-twig-component` | Packagist | All versions | 2.25.1 |
| `symfony/ux-twig-component` | Packagist | All versions | 2.25.1 |

## How do I fix CVE-2025-47946?

Upgrade symfony/ux-live-component to 2.25.1 or later.

## Is CVE-2025-47946 being exploited?

There is no known exploitation of CVE-2025-47946 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-47946 and fix it if it is affected.

What it is: CVE-2025-47946 is a medium-severity cross-site scripting vulnerability in symfony ux, published on 19 May 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-47946 in the wild and no public exploit code.

Affected packages and fixed versions:
- symfony/ux-live-component (Packagist): affected all versions; fixed in 2.25.1
- symfony/ux-live-component (Packagist): affected all versions; fixed in 2.25.1
- symfony/ux-twig-component (Packagist): affected all versions; fixed in 2.25.1
- symfony/ux-twig-component (Packagist): affected all versions; fixed in 2.25.1

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-2025-47946/ (Markdown: https://insights.sbomify.com/CVE-2025-47946/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-47946
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-47946
- OSV: https://osv.dev/vulnerability/CVE-2025-47946

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-47946/
Summaries are generated and may contain mistakes; the official description above is the record.