{"id":"CVE-2019-11728","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-11728","generatedAt":"2026-10-28T20:23:33.961Z","title":"The HTTP Alternative Services header, Alt-Svc, can be used by a malicious site to scan all TCP ports of any host that the accessible to a user when web content is loaded.","description":"The HTTP Alternative Services header, Alt-Svc, can be used by a malicious site to scan all TCP ports of any host that the accessible to a user when web content is loaded. This vulnerability affects Firefox < 68.","published":"2019-07-23T14:15:17.000Z","lastModified":"2026-06-17T02:13:31.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N"},"cwe":["CWE-668"],"affected":["mozilla/firefox","opensuse/leap"],"epss":{"score":0.01117,"percentile":0.65927,"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 (1.12%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1552993","tags":["Issue Tracking","Permissions Required","Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://security.gentoo.org/glsa/201908-12","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-21/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1552993","tags":["Issue Tracking","Permissions Required","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/201908-12","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-21/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-11728","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."}