CVE-2026-81887
Livewire is a full-stack framework for Laravel.
Overview
CVE-2026-81887 is a known-severity vulnerability. It was published on August 31, 2026.
Technical 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
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
References
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Frequently asked questions
What is CVE-2026-81887?
CVE-2026-81887 is a known-severity vulnerability. It was published on August 31, 2026.
How severe is CVE-2026-81887?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2026-81887?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-81887?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-81887 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.