cbcvebase.
CVE-2026-23524
published 2026-01-21

CVE-2026-23524: 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…

PriorityP266critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.88%
54.5th percentile
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

2 ranges
VendorProductVersion rangeFixed in
laravelreverb< 1.7.01.7.0
laravelreverb>= 0 < 1.7.01.7.0

Detection & IOCsextracted from sources · hover to see the quote

  • →Detect Laravel Reverb horizontal scaling enabled via environment variable — vulnerable code path is only triggered when REVERB_SCALING_ENABLED=true ↗
  • ·Vulnerability is only exploitable when horizontal scaling is enabled; disabling it entirely mitigates the risk even on unpatched versions ↗
  • ·Exploitability is significantly increased by the common practice of deploying Redis without authentication; unauthenticated Redis access allows an attacker to inject malicious serialized payloads directly into the channel ↗
  • ·Fix is available in laravel/reverb version 1.7.0; systems still running 1.6.3 or below with REVERB_SCALING_ENABLED=true and unauthenticated/network-exposed Redis are at critical (CVSS 9.8) risk ↗
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