CVE-2026-26861

HIGH

CleverTap Web SDK < 1.15.2 - Cross-Site Scripting via PostMessage Origin Validation Bypass

Title source: llm
STIX 2.1

Description

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

References (3)

Core 3

Scores

CVSS v3 8.3
EPSS 0.0018
EPSS Percentile 7.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-346
Status published
Products (2)
clevertap/clevertap_web_sdk < 1.15.2
npm/clevertap-web-sdk 0 - 1.15.3npm
Published Feb 27, 2026
Tracked Since Feb 28, 2026