Laravel reverb up to 1.6.x unserialize deserialization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Laravel reverb up to 1.6.x. Impacted is the function unserialize. This manipulation causes deserialization. The identification of this vulnerability is CVE-2026-23524. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Laravel reverb up to 1.6.x. It has been declared as critical. Affected by this vulnerability is the function unserialize. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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).

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-23524 since 01/13/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.7.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 9ec26f8ffbb701f84920dd0bb9781a1797591f1a is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• Laravel

Name

• reverb

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6

License

• open-source

Website

• Product: https://github.com/laravel/reverb/

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