This vulnerability affects Laravel Reverb versions prior to v1.7.0 when horizontal scaling is enabled (REVERB_SCALING_ENABLED=true).
The exploitability of this vulnerability is increased because Redis servers are commonly deployed without authentication.
With horizontal scaling enabled, Reverb servers communicate via Redis PubSub. Reverb previously passed data from the Redis channel directly into PHP’s unserialize() function without restricting which classes could be instantiated.
Risk: Remote Code Execution (RCE)
This vulnerability is fixed in Laravel Reverb v1.7.0.
Update your dependency to laravel/reverb: ^1.7.0 immediately.
If you cannot upgrade to v1.7.0, you should apply the following mitigations:
REVERB_SCALING_ENABLED=false to bypass the vulnerable logic entirely.This vulnerability was discovered and responsibly reported by Mohammad Yaser Abo-Elmaaty @m0h4mmad
{
"severity": "CRITICAL",
"github_reviewed_at": "2026-01-21T15:40:24Z",
"github_reviewed": true,
"nvd_published_at": "2026-01-21T22:15:50Z",
"cwe_ids": [
"CWE-502"
]
}