CVE-2026-81887

Livewire DOM-based cross-site scripting during client-side state handling

Published Aug 31, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-g3hc-697w-wm82 Livewire DOM-based cross-site scripting during client-side state handling
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Livewire
Livewire livewire
Vendors & Products Livewire
Livewire livewire
Type Values Removed Values Added
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.
Title Livewire DOM-based cross-site scripting during client-side state handling
Weaknesses CWE-1321
CWE-79
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 3, 2026, 6:03 PM
Reserved
Aug 27, 2026, 5:48 PM
Status
Deferred
Published
Aug 31, 2026, 9:17 PM
Modified
Sep 9, 2026, 9:09 PM