CVE-2025-11829: Five9 Live Chat <= 1.1.2 - Authenticated (Contributor+) Stored Cross-Site Scripting

Severity: medium (CVSS 6.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-11-11 · updated 2026-10-18
Weakness: CWE-79

Description

The Five9 Live Chat plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'toolbar' attribute of the [five9-chat] shortcode in all versions up to, and including, 1.1.2. This is due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

Five9 Live Chat: through 1.1.2

References

https://plugins.trac.wordpress.org/browser/five9/tags/1.1.2/includes/class-widget.php#L151
https://www.wordfence.com/threat-intel/vulnerabilities/id/28548108-a004-4aeb-a0ad-269a73a71331?source=cve

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