CVE Catalog

CVE-2026-81887

MediumCVSS 5.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.50%

41th percentile - higher than 41% of all known CVEs

Summary

Livewire from version 3.0.0-beta.1 to 3.8.3 and 4.3.4 has a vulnerability in the dot-notated query-string parser that accepts __proto__, constructor, and prototype path segments and creates inherited objects. Client-side state handlers treat inherited properties as trusted effects, allowing an unauthenticated attacker to execute arbitrary JavaScript in the application's origin when a user opens a crafted URL.

Risk Assessment

An attacker can execute malicious scripts in the victim's browser, potentially leading to data theft, session hijacking, or other harmful actions within the application context.

Recommendation

Update Livewire to version 3.8.3 or 4.3.4, which include a fix blocking dangerous path segments.

Related vulnerabilities

Original NVD description (English source)

Livewire is a full-stack framework for Laravel. From 3.0.0-beta.1 until 3.8.3 and 4.3.4, the dot-notated query-string parser in js/plugins/history/index.js, including fromQueryString() and insertDotNotatedValueIntoData(), accepts the __proto__, constructor, and prototype path segments and creates inherited objects. Client-side state handlers then access effects.html, effects.js, effects.xjs, and effects.scripts without Object.prototype.hasOwnProperty.call(), allowing inherited attacker-controlled state to be treated as trusted effects. An unauthenticated attacker can craft a URL that, when opened by a user, executes arbitrary JavaScript in the affected application's origin. Exploitation requires user interaction and does not bypass server-side authorization or grant privileges beyond the affected user. This issue is fixed in versions 3.8.3 and 4.3.4.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS