HIGH8.3
GHSA-j5mf-6rh3-rhgg
CleverTap Web SDK is vulnerable to DOM-based XSS via handleCustomHtmlPreviewPostMessageEvent function
Quick fix
GHSA-j5mf-6rh3-rhgg — clevertap-web-sdk: upgrade to the fixed version with the command below.
npm install clevertap-web-sdk@1.15.3Details
CleverTap Web SDK version 1.15.2 and earlier is vulnerable to Cross-site Scripting (XSS) via window.postMessage. The handleCustomHtmlPreviewPostMessageEvent function in src/util/campaignRender/nativeDisplay.js performs insufficient origin validation using the includes() method, which can be bypassed by an attacker using a subdomain.
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-26861[ADVISORY]
- https://github.com/CleverTap/clevertap-web-sdk/issues/424[WEB]
- https://github.com/CleverTap/clevertap-web-sdk/pull/417[WEB]
- https://github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03[WEB]
- https://github.com/CleverTap/clevertap-web-sdk[PACKAGE]
- https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/util/campaignRender/nativeDisplay.js#L118-L121[WEB]