Auth0-PHP SDK Deserialization of Untrusted Data vulnerability
Overview The Auth0 PHP SDK contains 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.
Am I Affected? You are affected by this vulnerability if you meet the following preconditions:
- Applications using the Auth0-PHP SDK, versions between 8.0.0-BETA3 to 8.3.0.
- Applications using the following SDKs that rely on the Auth0-PHP SDK versions between 8.0.0-BETA3 to 8.3.0: a. Auth0/symfony, b. Auth0/laravel-auth0, c. Auth0/wordpress.
Fix Upgrade Auth0/Auth0-PHP to 8.3.1.
Acknowledgement Okta would like to thank Andreas Forsblom for discovering this vulnerability.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | auth0/auth0-php | >= 8.0.0-BETA3, < 8.3.1 | 8.3.1 |
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://nvd.nist.gov/vuln/detail/CVE-2025-48951
- https://github.com/auth0/auth0-PHP/commit/04b1f5daa8bdfebc5e740ec5ca0fb2df1648a715
- https://github.com/auth0/auth0-PHP
- CVSS 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- Weakness (CWE)
CWE-502- Platform
- Composer
- Package
auth0/auth0-php- Disclosed
- 04.06.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-v9m8-9xxp-q492 - CC BY 4.0
Vulnerability history: auth0/auth0-php
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 5
- First → latest
- 05.2025 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 1
- Medium 1
- Low 1
Disclosures per year
- 2025: 4
- 2026: 1
-
Auth0-PHP SDK Deserialization of Untrusted Data vulnerability this entry
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