CVE-2026-81887
Severity CVSS v4.0:
MEDIUM
Type:
CWE-79
Cross-Site Scripting (XSS)
Publication date:
31/08/2026
Last modified:
31/08/2026
Description
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.
Impact
Base Score 4.0
5.10
Severity 4.0
MEDIUM
References to Advisories, Solutions, and Tools
- https://github.com/livewire/livewire/commit/11ebe646f7e81dde2d714815da8b3019d058561e
- https://github.com/livewire/livewire/pull/10467
- https://github.com/livewire/livewire/releases/tag/v3.8.3
- https://github.com/livewire/livewire/releases/tag/v4.3.4
- https://github.com/livewire/livewire/security/advisories/GHSA-g3hc-697w-wm82