CVE-2026-26862: Clevertap Web SDK

High severity, CVSS 8.3. EPSS: 0.5% chance of exploitation in the next 30 days.

CleverTap Web SDK version 1.15.2 and earlier is vulnerable to DOM-based Cross-Site Scripting (XSS) via window.postMessage in the Visual Builder module. The origin validation in src/modules/visualBuilder/pageBuilder.js (lines 56-60) uses the includes() method to verify the originUrl contains "dashboard.clevertap.com", which can be bypassed by an attacker using a crafted subdomain

Affected products

• Clevertap Clevertap Web SDK: up to and including 1.15.2

Published 2026-02-27. Last modified 2026-06-17.