Auth0-PHP SDK Deserialization of Untrusted Data vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

9.3 · 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 · score source

EPSS

• CVE-2025-48951: 0.75% estimated exploitation activity in the next 30 days; percentile 55.02 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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: 1. Applications using the Auth0-PHP SDK, versions between 8.0.0-BETA3 to 8.3.0. 2. 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.

Published by the source

4 Jun 2025, 20:31 UTC

Last modified by the source

4 Jun 2025, 22:56 UTC

Source last checked

26 Oct 2026, 14:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v9m8-9xxp-q492

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2025-48951

Advisory: Auth0-PHP SDK Deserialization of Untrusted Data vulnerability
IDs: CVE-2025-48951, GHSA-v9m8-9xxp-q492
Record: https://patchnext.com/advisories/cve-2025-48951 (revision 1, source checked 26 Oct 2026, 14:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: auth0/auth0-php 8.3.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist auth0/auth0-php: affected >= 8.0.0-BETA3, < 8.3.1; fixed in 8.3.1

## Suggested inspection (read-only)
- Packagist auth0/auth0-php: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on auth0/auth0-php.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v9m8-9xxp-q492 (GitHub-reviewed advisory GHSA-v9m8-9xxp-q492 lists affected ranges: Packagist auth0/auth0-php >=8.0.0-BETA3 <8.3.1)

Commands are suggestions: review each one before running it.