Auth0 Symfony SDK has Insufficient Entropy in Cookie Encryption
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:
- It uses the Auth0 Symfony SDK, versions between 5.0.0 and 5.7.0
- Auth0 Symfony SDK using the Auth0-PHP SDK versions between 8.0.0 to 8.18.0.
Resolution
Upgrade Auth0/symfony-auth0 to version 5.8.0 or greater.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | auth0/symfony | >= 5.0.0, < 5.8.0 | 5.8.0 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N- Weakness (CWE)
CWE-331- Platform
- Composer
- Package
auth0/symfony- Disclosed
- 03.04.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-ghc5-95c2-vwcv - CC BY 4.0
Vulnerability history: auth0/symfony
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
- 6
- First → latest
- 05.2025 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 1
- Medium 2
- Low 1
Disclosures per year
- 2025: 4
- 2026: 2
-
Auth0 Symfony SDK has Insufficient Entropy in Cookie Encryption this entry
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