CVE-2026-26861

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

CVSS v3 8.3 HIGH

8.3^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/util/campaignRender/nativeDisplay.js#L118-L121	Product
https://github.com/CleverTap/clevertap-web-sdk/issues/424	Exploit Issue Tracking Vendor Advisory
https://github.com/CleverTap/clevertap-web-sdk/pull/417	Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:clevertap:clevertap_web_sdk:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-02-27 18:16

Updated : 2026-03-03 18:46

NVD link : CVE-2026-26861

Mitre link : CVE-2026-26861

CVE.ORG link : CVE-2026-26861

JSON object : View

Products Affected

clevertap

clevertap_web_sdk

CWE

CWE-346

Origin Validation Error

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