How severe is CVE-2026-23524?

CVE-2026-23524 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-23524 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23524?

CVE-2026-23524 affects Laravel Reverb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23524?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-23524 have an EU (EUVD) identifier?

Yes. CVE-2026-23524 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3681.

When was CVE-2026-23524 published?

CVE-2026-23524 was published on 2026-01-21 and last updated on 2026-06-17.

CVE-2026-23524

CVE-2026-23524 is a critical-severity vulnerability in Laravel Reverb with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3681
Weakness: CWE-502
Affected product: Laravel Reverb
Published: 2026-01-21
Last modified: 2026-06-17

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).

Frequently asked questions

What is CVE-2026-23524?: 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).
How severe is CVE-2026-23524?: CVE-2026-23524 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-23524 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23524?: CVE-2026-23524 affects Laravel Reverb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23524?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-23524 have an EU (EUVD) identifier?: Yes. CVE-2026-23524 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3681.
When was CVE-2026-23524 published?: CVE-2026-23524 was published on 2026-01-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:laravel:reverb:*:*:*:*:*:*:*:*

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