high8.3
CVE-2026-26862
CleverTap Web SDK is vulnerable to DOM-based Cross-Site Scripting (XSS) via window.postMessage
Impact
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
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | clevertap-web-sdk | < 1.15.3 | 1.15.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Clevertap | Clevertap Web Sdk | through 1.15.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/modules/visualBuilder/pageBuilder.js#L56-L60
- https://github.com/CleverTap/clevertap-web-sdk/issues/442
- https://github.com/CleverTap/clevertap-web-sdk/pull/417
- https://github.com/advisories/GHSA-jfrq-hj9f-c8qx
- https://nvd.nist.gov/vuln/detail/CVE-2026-26862
- https://github.com/CleverTap/clevertap-web-sdk/commit/766f75f0c9082a27eb0b59c9fa4b0d9b19ba3d10
- https://github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03