CVE-2026-26862
February 27, 2026
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
https://github.com/CleverTap/clevertap-web-sdk.git (GITHUB):
Affected version(s) >=v1.0.0-beta.0 <v1.15.2Fix Suggestion:
Update to version v1.15.2clevertap-web-sdk (NPM):
Affected version(s) >=1.0.0-beta.1 <1.15.3Fix Suggestion:
Update to version 1.15.3clevertap-web-sdk (NPM):
Affected version(s) >=1.0.0-beta.1 <1.15.2Fix Suggestion:
Update to version 1.15.2Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
LOW
Weakness Type (CWE)
EPSS
Base Score:
0.01
