---
title: "GHSA-98j6-67v3-mw34: Auth0 Symfony SDK Deserialization of Untrusted Data vulnerability"
url: https://erroneo.us/security/ghsa/GHSA-98j6-67v3-mw34/
description: "GHSA-98j6-67v3-mw34 (critical, Composer (PHP)): Auth0 Symfony SDK Deserialization of Untrusted Data vulnerability. Overview The Auth0 Symfony SDK contains a…"
type: advisory
section: "Security Digest"
date_published: 2025-06-06
date_modified: 2025-06-06
publisher: erroneo.us
author: erroneo.us Security Desk
ghsa: "GHSA-98j6-67v3-mw34"
license: All rights reserved. Quote with attribution and a link.
---

# GHSA-98j6-67v3-mw34: Auth0 Symfony SDK Deserialization of Untrusted Data vulnerability

## Affected packages

- Composer (PHP) `auth0/symfony` >= 5.0.0-BETA0, <= 5.0.0 → fixed: 5.1.0

## Details

Overview The Auth0 Symfony SDK contains a critical vulnerability due to insecure deserialization of cookie data. If exploited, since SDKs process cookie content without prior authentication, a threat actor could send a specially crafted cookie containing malicious serialized data. Am I Affected? You are affected by this vulnerability if you meet the following preconditions: 1. Applications using the Auth0 Symfony SDK, versions between 5.0.0 BETA-0 to 5.0.0. 2. Auth0 Symfony SDK uses the Auth0-PHP SDK with version 8.0.0-BETA3 to 8.3.0. Fix Upgrade Auth0/symfony to the latest version (v5.4.0). Acknowledgement Okta would like to thank Andreas Forsblom for discovering this vulnerability.

## Sources

- [GitHub Advisory GHSA-98j6-67v3-mw34](https://github.com/advisories/GHSA-98j6-67v3-mw34)
- [github.com](https://github.com/auth0/auth0-PHP/security/advisories/GHSA-v9m8-9xxp-q492)
- [github.com](https://github.com/auth0/laravel-auth0/security/advisories/GHSA-c42h-56wx-h85q)
- [github.com](https://github.com/auth0/symfony/security/advisories/GHSA-98j6-67v3-mw34)
- [github.com](https://github.com/auth0/wordpress/security/advisories/GHSA-862m-5253-832r)
- [nvd.nist.gov](https://nvd.nist.gov/vuln/detail/CVE-2025-48951)

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Source page: https://erroneo.us/security/ghsa/GHSA-98j6-67v3-mw34/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt