Summary
Livewire DOM-based cross-site scripting during client-side state handling
Workarounds
There is no known workaround at this time. Users are strongly advised to upgrade to a patched version immediately.
Impact
In Livewire v3 (≤ 3.8.2) and v4 (≤ 4.3.3), a vulnerability allows unauthenticated attackers to execute arbitrary JavaScript in the origin of an affected application in specific scenarios. The issue stems from how certain client-side component state is handled. This vulnerability does not affect prior major versions. Exploitation requires user interaction, but does not require authentication or prior access to the application. The issue does not bypass server-side authorisation and grants an attacker no privileges beyond those the affected user already holds.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This issue has been patched in Livewire v3.8.3 and v4.3.4. All users are strongly encouraged to upgrade to these versions or later as soon as possible.
Frequently Asked Questions
- What is CVE-2026-81887? CVE-2026-81887 is a medium-severity cross-site scripting (XSS) vulnerability in livewire/livewire (composer), affecting versions >= 3.0.0-beta.1, <= 3.8.2. It is fixed in 3.8.3, 4.3.4. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of livewire/livewire are affected by CVE-2026-81887? livewire/livewire (composer) versions >= 3.0.0-beta.1, <= 3.8.2 is affected.
- Is there a fix for CVE-2026-81887? Yes. CVE-2026-81887 is fixed in 3.8.3, 4.3.4. Upgrade to this version or later.
- Is CVE-2026-81887 exploitable, and should I be worried? Whether CVE-2026-81887 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-81887 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-81887?
- Upgrade
livewire/livewireto 3.8.3 or later - Upgrade
livewire/livewireto 4.3.4 or later
- Upgrade