CVE-2026-26861
Cross-Site Scripting in CleverTap Web SDK via postMessage
Publication date: 2026-02-27
Last updated on: 2026-03-03
Assigner: MITRE
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| clevertap | clevertap_web_sdk | to 1.15.2 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-346 | The product does not properly verify that the source of data or communication is valid. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CleverTap Web SDK version 1.15.2 and earlier contains a Cross-Site Scripting (XSS) vulnerability via the window.postMessage API. Specifically, the function handleCustomHtmlPreviewPostMessageEvent in the file src/util/campaignRender/nativeDisplay.js does not properly validate the origin of messages. It uses the includes() method for origin validation, which can be bypassed by an attacker using a subdomain, allowing malicious scripts to be executed.
How can this vulnerability impact me? :
This vulnerability can allow an attacker to execute malicious scripts in the context of the affected web application. This can lead to unauthorized actions such as stealing user data, session hijacking, or performing actions on behalf of the user without their consent.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know