# Auth0 Symfony SDK Deserialization of Untrusted Data vulnerability

Source: https://junglewise.ai/threats/auth0-symfony-sdk-deserialization-of-untrusted-data-vulnerability-8935e08b  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-06-06  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 4 · Published 2025-06-06

Auth0 Symfony SDK Deserialization of Untrusted Data vulnerability

Technologies: [auth0/symfony (Packagist)](https://junglewise.ai/threats/technologies/auth0-symfony). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 4, published 6 June 2025.

**Which products and versions are affected?** auth0/symfony (Packagist) ECOSYSTEM:introduced=5.0.0-BETA0,fixed=5.1.0.

**Is there a fix for This vulnerability?** Yes. auth0/symfony (Packagist): upgrade to 5.1.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run auth0/symfony (Packagist) 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

- auth0/symfony (Packagist): upgrade to 5.1.0 or later

  ```sh
  composer require auth0/symfony:^5.1.0
  ```


## Affected products

- auth0/symfony (Packagist) ECOSYSTEM:introduced=5.0.0-BETA0,fixed=5.1.0

## Related threats

- [Auth0 Symfony SDK sensitive information exposure via URL query parameters](https://junglewise.ai/threats/cve-2026-50157-auth0-symfony-sdk-sensitive-information-exposure-via-url-query)
- [Auth0 Symfony SDK has Insufficient Entropy in Cookie Encryption](https://junglewise.ai/threats/auth0-symfony-sdk-has-insufficient-entropy-in-cookie-encryption-879e650c)
- [Auth0 Symfony SDK has Improper Audience Validation via Auth0-PHP SDK](https://junglewise.ai/threats/auth0-symfony-sdk-has-improper-audience-validation-via-auth0-php-sdk-1672c32f)
- [Auth0 Symfony SDK Does Not Properly Handle File Types in Bulk User Import](https://junglewise.ai/threats/auth0-symfony-sdk-does-not-properly-handle-file-types-in-bulk-user-e11aaa8c)
- [Auth0 Symfony SDK Vulnerable to Brute Force Authentication Tags of CookieStore Sessions](https://junglewise.ai/threats/auth0-symfony-sdk-vulnerable-to-brute-force-authentication-tags-of-56db288e)