CVE-2026-23524 Laravel Redis Horizontal Scaling Insecure Deserialization
Attackers can achieve remote code execution via insecure deserialization in Laravel Reverb when horizontal scaling is enabled and Redis is accessible.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23524?
CVE-2026-23524 is a critical unsafe deserialization vulnerability in laravel reverb, published on 21 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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).
Weakness: CWE-502
Which versions are affected by CVE-2026-23524?
2 open source packages ship an affected version, including laravel/reverb. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
laravel/reverb Packagist | All versions | 1.7.0 |
laravel/reverb Packagist | All versions | 1.7.0 |
Products include Laravel Reverb.
How do I fix CVE-2026-23524?
Upgrade laravel/reverb to 1.7.0 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-23524 being exploited?
There is no known exploitation of CVE-2026-23524 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-m27r-m6rx-mhm4.