Auth0 PHP SDK has Insufficient Entropy in Cookie Encryption

CRITICAL 9.8CVE-2026-34236 · GHSA-w3wc-44p4-m4j7 · Published 01/04/2026 · updated 26/10/2026

Package	Affected versions	Patched versions
auth0/auth0-php Packagist	`≥ 8.0.0, < 8.19.0`	`8.19.0`
auth0-php auth0	`≥ 8.0.0, < 8.19.0`	`8.19.0`

Description

Impact

In applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat actors brute-forcing the encryption key and forging session cookies.

Am I Affected?

Consumers are affected if their application meets the following preconditions:

Their application is using the Auth0-PHP SDK, versions between 8.0.0 and 8.18.0
Their application is using the Auth0-PHP SDK, or the following SDKs that rely on the Auth0-PHP SDK:
- Auth0/symfony,
- Auth0/laravel0-auth0, or
- Auth0/wordpress

Resolution

Upgrade Auth0/Auth0-PHP to version 8.19.0 or greater.

NVD description

Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. From version 8.0.0 to before version 8.19.0, in applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat actors brute-forcing the encryption key and forging session cookies. This issue has been patched in version 8.19.0.

References

auth0/auth0-PHP security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2026-34236 · ADVISORY
auth0/auth0-PHP · PACKAGE
auth0/auth0-PHP release 8.19.0 · WEB

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