CVE-2026-26861

CVSS 8.3 HIGHEPSS 0.2%CWE-346

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 8.3EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

27 Feb 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

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

Affected products

n/a · n/a

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References

https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/util/campaignRender/nativeDisplay.js#L118-L121 https://github.com/CleverTap/clevertap-web-sdk/issues/424 https://github.com/CleverTap/clevertap-web-sdk/pull/417