clevertap/clevertap-web-sdk · Security
CleverTap Web SDK is vulnerable to DOM-based Cross-Site Scripting (XSS) via window.postMessage
- GHSA ID
- GHSA-jfrq-hj9f-c8qx
- CVE ID
- CVE-2026-26862
- Severity
- high
- Published
- Updated
- CVSS
- 8.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
- CVSS v3
- 8.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
Description
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.
CWEs
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-26862 ↗
- https://github.com/CleverTap/clevertap-web-sdk/issues/442 ↗
- https://github.com/CleverTap/clevertap-web-sdk/pull/417 ↗
- https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/modules/visualBuilder/pageBuilder.js#L56-L60 ↗
- https://github.com/CleverTap/clevertap-web-sdk/commit/766f75f0c9082a27eb0b59c9fa4b0d9b19ba3d10 ↗
- https://github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03 ↗
- https://github.com/advisories/GHSA-jfrq-hj9f-c8qx ↗