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Critical severityOSV Advisory· Published Jan 21, 2026· Updated Jan 22, 2026

Laravel Redis Horizontal Scaling Insecure Deserialization

CVE-2026-23524

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).

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
laravel/reverbPackagist
< 1.7.01.7.0

Affected products

1

Patches

1
9ec26f8ffbb7

Add allowed classes (#360)

https://github.com/laravel/reverbTaylor OtwellJan 6, 2026via ghsa
commit
1 file changed · +7 −2
  • src/Protocols/Pusher/PusherPubSubIncomingMessageHandler.php+7 −2 modified
    @@ -2,7 +2,10 @@
 
 namespace Laravel\Reverb\Protocols\Pusher;
 
+use Laravel\Reverb\Application;
 use Laravel\Reverb\Protocols\Pusher\Contracts\ChannelManager;
+use Laravel\Reverb\Protocols\Pusher\MetricType;
+use Laravel\Reverb\Protocols\Pusher\PendingMetric;
 use Laravel\Reverb\Servers\Reverb\Contracts\PubSubIncomingMessageHandler;
 
 class PusherPubSubIncomingMessageHandler implements PubSubIncomingMessageHandler
@@ -18,7 +21,7 @@ public function handle(string $payload): void
 
         $this->processEventListeners($event);
 
-        $application = unserialize($event['application'] ?? null);
+        $application = unserialize($event['application'] ?? null, ['allowed_classes' => [Application::class]]);
 
         $except = isset($event['socket_id']) ?
             app(ChannelManager::class)->for($application)->connections()[$event['socket_id']] ?? null
@@ -31,7 +34,9 @@ public function handle(string $payload): void
                 $except?->connection()
             ),
             'metrics' => app(MetricsHandler::class)->publish(
-                unserialize($event['payload'])
+                unserialize($event['payload'], ['allowed_classes' => [
+                    Application::class, PendingMetric::class, MetricType::class
+                ]])
             ),
             'terminate' => collect(app(ChannelManager::class)->for($application)->connections())
                 ->each(function ($connection) use ($event) {

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

8

News mentions

0

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