CVE-2026-23524: laravel reverb Deserialization of Untrusted Data

Vulnerability summary

CVE-2026-23524 is a critical (CVSS 9.8) Deserialization of Untrusted Data vulnerability in laravel reverb. EPSS estimates a 0.98% chance of exploitation in the next 30 days, higher than 61.5% of scored vulnerabilities.

Timeline

1. 21-01-2026
   PublishedVulnerability first disclosed.
2. 22-01-2026
   Last modifiedVulnerability information updated.

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).

• CWE-502Deserialization of Untrusted DataThe product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.