{"id":"CVE-2026-26861","aliases":["EUVD-2026-9038","GHSA-j5mf-6rh3-rhgg"],"status":"published","title":"CleverTap Web SDK  is vulnerable to DOM-based XSS via handleCustomHtmlPreviewPostMessageEvent function","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","severity":{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-12","score":0.00205,"percentile":0.10625,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-346","CWE-79"],"published":"2026-02-27T00:00:00Z","modified":"2026-10-28T02:31:02Z","fixes":[{"ecosystem":"npm","package":"clevertap-web-sdk","fixed_in":["1.15.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"clevertap-web-sdk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.15.3"}]}]},{"source":"osv","ecosystem":"npm","package":"clevertap-web-sdk","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.15.3"}]}]}],"products":[{"vendor":"clevertap","product":"clevertap_web_sdk"}],"references":[{"url":"https://github.com/CleverTap/clevertap-web-sdk/issues/424","tags":["Exploit","Issue Tracking","Vendor Advisory","report","web"]},{"url":"https://github.com/CleverTap/clevertap-web-sdk/pull/417","tags":["Patch","fix","web"]},{"url":"https://github.com/CleverTap/clevertap-web-sdk/blob/cf1b65d/src/util/campaignRender/nativeDisplay.js#L118-L121","tags":["Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26861","tags":["advisory"]},{"url":"https://github.com/CleverTap/clevertap-web-sdk/commit/84695b726a751614ddc3a4f71382c239c5833e03","tags":["web"]},{"url":"https://github.com/advisories/GHSA-j5mf-6rh3-rhgg"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26861.json","tags":["advisory"]},{"url":"https://github.com/CleverTap/clevertap-web-sdk","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-26861","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","status":"published","published":"2026-02-27T00:00:00Z","modified":"2026-02-27T19:42:58.097Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high","assessor":"adp"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T13:38:32.13011Z"}],"euvd":[{"id":"EUVD-2026-9038","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","status":"published","published":"2026-02-27T00:00:00Z","modified":"2026-02-27T19:42:58Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high"}],"updated_at":"2026-11-02T19:48:13.609806Z"}],"ghsa":[{"id":"GHSA-j5mf-6rh3-rhgg","title":"CleverTap Web SDK  is vulnerable to DOM-based XSS via handleCustomHtmlPreviewPostMessageEvent function","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.","status":"published","published":"2026-02-27T18:31:06Z","modified":"2026-03-01T01:26:28Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high"}],"cwes":["CWE-79","CWE-346"],"updated_at":"2026-11-02T14:39:30.031684Z"}],"nvd":[{"id":"CVE-2026-26861","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","status":"published","published":"2026-02-27T18:16:12.043Z","modified":"2026-06-17T10:26:21.957Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high","assessor":"secondary"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:12:07.420927Z"}],"osv":[{"id":"CVE-2026-26861","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","status":"published","published":"2026-02-27T00:00:00Z","modified":"2026-10-28T02:31:02.238158388Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high"}],"updated_at":"2026-11-02T15:44:59.80315Z"},{"id":"GHSA-j5mf-6rh3-rhgg","title":"CleverTap Web SDK  is vulnerable to DOM-based XSS via handleCustomHtmlPreviewPostMessageEvent function","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.","status":"published","published":"2026-02-27T18:31:06Z","modified":"2026-03-04T15:12:09.21704Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","level":"high"}],"cwes":["CWE-346","CWE-79"],"updated_at":"2026-11-02T15:46:49.977351Z"}]}}