Secuno
ENNL
Book demo

CVE-2026-26861

Clevertap Web Sdk cross-site scripting (XSS)

8.3 HIGHPublic exploitEPSS 0.22%
  1. Published27 Feb 2026

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

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

Affected products

Clevertap Web Sdk≤ 1.15.2

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-773638.8
obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian…
CVE-2026-1092868.1
Open WebUI from 0.7.0 before 0.11.4 contains a cross-origin message handling…
CVE-2026-91919.6
Progress MarkLogic Server 12.x releases before 12.1.0 and 11.x releases before 11.3.7…
CVE-2026-1082619.3
Tina is a headless content management system. Prior to tinacms 3.14.0 and @tinacms/app…
CVE-2026-1057838.0
Joplin is an open source note-taking and to-do application that organises notes and…
CVE-2026-1040569.8
Authlib version 1.7.2 and below contains a vulnerability where discovery JSON metadata…

Frequently asked

Is CVE-2026-26861 being actively exploited?

CVE-2026-26861 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.22%.

How severe is CVE-2026-26861?

CVE-2026-26861 has a CVSS 3.1 base score of 8.3, rated high. EPSS estimates a 0.22% probability of exploitation.

Which products are affected by CVE-2026-26861?

Affected products include Clevertap Web Sdk.

How do I fix CVE-2026-26861?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-26861 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.