Vulnerability Description
Laravel Reverb provides a real-time WebSocket communication backend for Laravel applications. In versions 1.6.3 and below, Reverb passes data from the Redis channel directly into PHP’s unserialize() function without restricting which classes can be instantiated, which leaves users vulnerable to Remote Code Execution. The exploitability of this vulnerability is increased because Redis servers are commonly deployed without authentication, but only affects Laravel Reverb when horizontal scaling is enabled (REVERB_SCALING_ENABLED=true). This issue has been fixed in version 1.7.0. As a workaround, require a strong password for Redis access and ensure the service is only accessible via a private network or local loopback, and/or set REVERB_SCALING_ENABLED=false to bypass the vulnerable logic entirely (if the environment uses only one Reverb node).
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Laravel | Reverb | < 1.7.0 |
Related Weaknesses (CWE)
References
- https://cwe.mitre.org/data/definitions/502.htmlTechnical Description
- https://github.com/laravel/reverb/commit/9ec26f8ffbb701f84920dd0bb9781a1797591f1Patch
- https://github.com/laravel/reverb/releases/tag/v1.7.0ProductRelease Notes
- https://github.com/laravel/reverb/security/advisories/GHSA-m27r-m6rx-mhm4MitigationVendor Advisory
- https://laravel.com/docs/12.x/reverb#scalingTechnical Description
FAQ
What is CVE-2026-23524?
CVE-2026-23524 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Laravel Reverb provides a real-time WebSocket communication backend for Laravel applications. In versions 1.6.3 and below, Reverb passes data from the Redis channel directly into PHP’s unserialize() f...
How severe is CVE-2026-23524?
CVE-2026-23524 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-23524?
Check the references section above for vendor advisories and patch information. Affected products include: Laravel Reverb.