How severe is CVE-2026-81887?

No CVSS score has been assigned to CVE-2026-81887 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-81887?

CVE-2026-81887 affects the following packages: livewire/livewire (Packagist), livewire/livewire (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-81887?

Update livewire/livewire to 3.8.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-81887 is resolved across your whole dependency graph.

How do I detect CVE-2026-81887 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for livewire/livewire, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-81887 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-81887 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-81887 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-81887?

CVE-2026-81887 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 52th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-81887?

CVE-2026-81887 is classified as Cross-site Scripting (XSS) (CWE-79), CWE-1321 (CWE-1321). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-81887 published, and has it been updated?

CVE-2026-81887 was published on August 31, 2026 and was last updated on September 11, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2026-81887 — livewire

Fix: livewire/livewire@11ebe64

CVE-2026-81887 is a Cross-site Scripting (XSS) vulnerability in livewire/livewire. A fix is available for livewire/livewire — see the affected versions and patch details below.

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

Also known asGHSA-g3hc-697w-wm82

Published

Aug 31, 2026

Updated

Sep 11, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-81887.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs52th percentile — riskier than 52% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🐘livewire/livewire🐘livewire/livewire

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

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.

Patches

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.

Workarounds

There is no known workaround at this time. Users are strongly advised to upgrade to a patched version immediately.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`livewire/livewire`	≥ 3.0.0-beta.1&&< 3.8.3	3.8.3`composer require livewire/livewire:^3.8.3`
🐘Packagist	`livewire/livewire`	≥ 4.0.0-beta.1&&< 4.3.4	4.3.4`composer require livewire/livewire:^4.3.4`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for livewire/livewire, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update livewire/livewire to 3.8.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-81887 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### 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. ### Patches This issue