---
title: "CVE-2026-23524: Laravel Redis Horizontal Scaling Insecure Deserialization"
url: https://erroneo.us/security/cve/CVE-2026-23524/
description: "CVE-2026-23524 (laravel/reverb (Composer (PHP))): Laravel Reverb provides a real-time WebSocket communication backend for Laravel applications. In versions…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-01-21
date_modified: 2026-01-22
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-23524"
kev: false
cvss: 9.8
epss: 0.00976
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.0% , percentile 62: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 62% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes laravel/reverb (Composer (PHP)) < 1.7.0, fixed in 1.7.0 . Check your lockfile, including transitive dependencies.

## What it 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 (REVERBSCALINGENABLED=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 REVERBSCALINGENABLED=false to bypass the vulnerable logic entirely (if the environment uses only one Reverb node).

## Affected packages

- Composer (PHP) `laravel/reverb` < 1.7.0 → fixed: 1.7.0

## Affected products (CVE record)

- laravel reverb: < 1.7.0

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.98% probability of exploitation activity in the next 30 days; percentile 62.

## Sources

- [GitHub Advisory GHSA-m27r-m6rx-mhm4](https://github.com/advisories/GHSA-m27r-m6rx-mhm4)
- [CVE.org record CVE-2026-23524](https://www.cve.org/CVERecord?id=CVE-2026-23524)
- [NVD entry CVE-2026-23524](https://nvd.nist.gov/vuln/detail/CVE-2026-23524)
- [github.com](https://github.com/laravel/reverb/security/advisories/GHSA-m27r-m6rx-mhm4)
- [github.com](https://github.com/laravel/reverb/commit/9ec26f8ffbb701f84920dd0bb9781a1797591f1a)
- [cwe.mitre.org](https://cwe.mitre.org/data/definitions/502.html)
- [github.com](https://github.com/laravel/reverb/releases/tag/v1.7.0)
- [laravel.com](https://laravel.com/docs/12.x/reverb#scaling)
- [laravel.com](https://laravel.com/docs/reverb#scaling)

---
Source page: https://erroneo.us/security/cve/CVE-2026-23524/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt