CVE-2026-26862: CleverTap Web SDK is vulnerable to DOM-based Cross-Site Scripting (XSS) via window.postMessage
(updated )
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.
References
- github.com/CleverTap/clevertap-web-sdk
- github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/modules/visualBuilder/pageBuilder.js
- github.com/CleverTap/clevertap-web-sdk/commit/766f75f0c9082a27eb0b59c9fa4b0d9b19ba3d10
- github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03
- github.com/CleverTap/clevertap-web-sdk/issues/442
- github.com/CleverTap/clevertap-web-sdk/pull/417
- github.com/advisories/GHSA-jfrq-hj9f-c8qx
- nvd.nist.gov/vuln/detail/CVE-2026-26862
Code Behaviors & Features
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