CVE-2026-26861 | BDVDB-2026-317713 Detail

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

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact low. Attack vector: network.

Weaknesses#

CWE-346 Origin Validation Error

References#

Exploit#

No public exploit known

History#

Version 12026-02-27Record published in the CVE List.

Published

Published: 2026-02-27
Last modified: 2026-02-27

Vendor information

Vendor: Not stated
Product: Not stated

Score

8.3 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 10.6.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

No version data in the source record.

Scoring System

CVSS v4.0

Not available

CVSS v3.1

8.3 High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User Interaction	Required
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	Low

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).