{"id":"CVE-2018-5138","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-5138","generatedAt":"2026-10-29T03:02:27.554Z","title":"A spoofing vulnerability can occur when a malicious site with an extremely long domain name is opened in an Android Custom Tab (a browser panel inside another app) and the default browser is Firefox for Android.","description":"A spoofing vulnerability can occur when a malicious site with an extremely long domain name is opened in an Android Custom Tab (a browser panel inside another app) and the default browser is Firefox for Android. This could allow an attacker to spoof which page is actually loaded and in use. Note: this issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 59.","published":"2018-06-11T21:29:14.000Z","lastModified":"2026-06-17T01:59:42.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-20"],"affected":["mozilla/firefox"],"epss":{"score":0.01088,"percentile":0.65146,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.09%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/103386","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"http://www.securitytracker.com/id/1040514","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1432624","tags":["Issue Tracking","Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2018-06/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"http://www.securityfocus.com/bid/103386","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1040514","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1432624","tags":["Issue Tracking","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2018-06/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-5138","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}