Laravel Redis Horizontal Scaling Insecure Deserialization
Impact
This vulnerability affects Laravel Reverb versions prior to v1.7.0 when horizontal scaling is enabled (REVERB_SCALING_ENABLED=true).
The exploitability of this vulnerability is increased because Redis servers are commonly deployed without authentication.
With horizontal scaling enabled, Reverb servers communicate via Redis PubSub. Reverb previously passed data from the Redis channel directly into PHP’s unserialize() function without restricting which classes could be instantiated.
Risk: Remote Code Execution (RCE)
Patches
This vulnerability is fixed in Laravel Reverb v1.7.0.
Update your dependency to laravel/reverb: ^1.7.0 immediately.
Workarounds
If you cannot upgrade to v1.7.0, you should apply the following mitigations:
- Redis Security: Require a strong password for Redis access and ensure the service is only accessible via a private network or local loopback.
- Disable Scaling: If your environment uses only one Reverb node, set
REVERB_SCALING_ENABLED=falseto bypass the vulnerable logic entirely.
Credits
This vulnerability was discovered and responsibly reported by Mohammad Yaser Abo-Elmaaty @m0h4mmad
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | laravel/reverb | < 1.7.0 | 1.7.0 |
References
- https://github.com/laravel/reverb/security/advisories/GHSA-m27r-m6rx-mhm4
- https://nvd.nist.gov/vuln/detail/CVE-2026-23524
- https://github.com/laravel/reverb/commit/9ec26f8ffbb701f84920dd0bb9781a1797591f1a
- https://github.com/laravel/reverb
- https://github.com/laravel/reverb/releases/tag/v1.7.0
- https://laravel.com/docs/12.x/reverb#scaling
- https://laravel.com/docs/reverb#scaling
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-502- Platform
- Composer
- Package
laravel/reverb- Disclosed
- 21.01.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-m27r-m6rx-mhm4 - CC BY 4.0
Vulnerability history: laravel/reverb
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 10.2024 01.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 1
Disclosures per year
- 2024: 1
- 2025: 0
- 2026: 1
-
Laravel Redis Horizontal Scaling Insecure Deserialization this entry
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