CVE-2026-26862
HIGH8.3EPSS 0.02%CleverTap Web SDK is vulnerable to DOM-based Cross-Site Scripting (XSS) via window.postMessage
Published: 2/27/2026Modified: 3/4/2026
Also known as:GHSA-jfrq-hj9f-c8qx
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.
Affected packages (1)
- npm/clevertap-web-sdkfrom 0, < 1.15.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-26862
- PATCHhttps://github.com/CleverTap/clevertap-web-sdk
- WEBhttps://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/modules/visualBuilder/pageBuilder.js#L56-L60
- WEBhttps://github.com/CleverTap/clevertap-web-sdk/commit/766f75f0c9082a27eb0b59c9fa4b0d9b19ba3d10
- WEBhttps://github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03
- WEBhttps://github.com/CleverTap/clevertap-web-sdk/issues/442
- WEBhttps://github.com/CleverTap/clevertap-web-sdk/pull/417