Is this vulnerability remotely exploitable?

Yes. An attacker can exploit it remotely by hosting a malicious page on a crafted domain that passes the weak origin check and then causing a victim to load a site that includes the vulnerable CleverTap Web SDK with Visual Builder active.

Does an attacker need authenticated access to CleverTap or the application?

Not necessarily. The core requirement is the ability to send crafted `postMessage` calls from a controlled origin that passes the SDK's origin filter, and to get users to load the affected site. Application-level authentication may affect what data can be accessed or actions performed, but is not required to trigger the XSS itself.

What is the safest general fix pattern for developers?

Implement strict origin checking for all `postMessage` handlers using equality against a well-defined list of allowed origins, and validate and sanitize all message payloads before touching the DOM or executing any logic that can affect security-sensitive state.

Severity:

HIGH RISK

(8.3)

DOM-based Cross-Site Scripting (CWE-79) in CleverTap Web SDK Visual Builder postMessage Origin Check

CVE-2026-26862

Published:

Feb 27, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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CRITICAL RISK

CRITICAL

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SQL Injection via PostgreSQL Array/Row Expressions (CWE-89) in WeKnora Query Engine

Remote Code Execution via SQL Injection on the Database Server

March 7, 2026

Vulnerability Type

Category:

Cross-Site Scripting (XSS)

CWE:

CWE-79;CWE-829

Impact:

Client-Side Code Execution / Session Compromise

Severity:

HIGH RISK

(8.3)

CVSS Version:

3.1

Vulnerability Type

Category:

Cross-Site Scripting (XSS)

CWE:

CWE-79;CWE-829

Impact:

Client-Side Code Execution / Session Compromise

Severity:

HIGH RISK

(8.3)

CVSS Version:

3.1

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Ask AI for summary of CodeAnt

DOM-based Cross-Site Scripting (CWE-79) in CleverTap Web SDK Visual Builder postMessage Origin Check

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

CRITICAL RISK

CRITICAL

(9.9)

Command Injection in MCP Stdio Configuration Validation (CWE-78) in WeKnora

CRITICAL RISK

CRITICAL

(9.9)

SQL Injection via PostgreSQL Array/Row Expressions (CWE-89) in WeKnora Query Engine

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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