dbcve.org
ReverbFramework / library · Laravel

CVE-2026-23524

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-21
Fix available
A fix is available. Upgrade to 1.7.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Laravel Reverb versions 1.6.3 and below contain an insecure deserialization vulnerability where Redis channel data is passed directly to PHP's unserialize() without class whitelist restrictions, enabling remote code execution. This vulnerability is only exploitable when horizontal scaling is enabled via REVERB_SCALING_ENABLED=true and the Redis server is accessible (often without authentication in default deployments).

MitigationUpgrade Laravel Reverb to version 1.7.0 or higher to receive the patch; alternatively, disable horizontal scaling (REVERB_SCALING_ENABLED=false) or secure Redis access with authentication and network isolation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ReverbFramework / library
Affected:< 1.7.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Laravel Reverb version
    Check your composer.json or run 'composer show laravel/reverb' to see the installed version number
    Affected if version is below 1.7.0 (versions 1.6.3 and below are vulnerable)
  2. Verify horizontal scaling configuration
    Check if the environment variable REVERB_SCALING_ENABLED is set to true, or inspect your .env file and configuration for the scaling setting
    Affected if REVERB_SCALING_ENABLED is set to true (this enables the vulnerable Redis channel functionality)
  3. Confirm Redis is accessible by Reverb
    Inspect your Laravel/Reverb configuration to determine which Redis server is used for channel data, and verify network accessibility from the Reverb server
    Affected if Redis is reachable and used for scaling (the unserialize occurs on data retrieved from Redis)
  4. Assess Redis authentication status
    Check your Redis configuration and connection settings to determine if authentication (password) is required
    Affected if Redis accepts connections without authentication (default deployments often have no password set)

You are affected if Laravel Reverb is below version 1.7.0, horizontal scaling is enabled (REVERB_SCALING_ENABLED=true), and your Redis server is accessible without authentication protection.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.7.0 or later
Fixed in 1.7.0
Vendor patch github.com →
Interim mitigation

Upgrade Laravel Reverb to version 1.7.0 or higher to receive the patch; alternatively, disable horizontal scaling (REVERB_SCALING_ENABLED=false) or secure Redis access with authentication and network isolation.

Recommended fix High confidence

1.7.0

  1. Run `composer require laravel/reverb:^1.7.0` to upgrade to the fixed version, or update the laravel/reverb version constraint in composer.json to ^1.7.0 and run `composer update`
  2. After upgrading, verify the version by running `php artisan reverb:version` or checking composer.json
  3. Ensure Redis authentication is configured even after patching by setting REDIS_PASSWORD in your environment
  4. If immediate upgrade is not possible, set REVERB_SCALING_ENABLED=false in your environment to disable the vulnerable code path
  5. Alternatively, ensure Redis is bound to localhost/private network only and requires strong authentication

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Reverb Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-23524 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data