CVE-2026-26861

CleverTap Web SDK version 1.15.2 and earlier is vulnerable to Cross-Site Scripting (XSS) via window.postMessage

High · published February 27, 2026

CVSS v3.1
8.3
EPSS
0%
Percentile
13.0
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
8.3 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00230 · 13.0th percentile
Published
2026-02-27T00:00Z
EPSS history
Timeline
  • 27 FEB 00:00Z
    CleverTap Web SDK version 1.15.2 and earlier is vulnerable to Cross-Site Scripting (XSS) via window.postMessage
    cvelistv5