{"id":"CVE-2017-9233","url":"https://www.cyber-defence.io/tools/cve/CVE-2017-9233","generatedAt":"2026-10-28T22:18:52.945Z","title":"XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.","description":"XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.","published":"2017-07-25T20:29:00.000Z","lastModified":"2026-10-08T21:17:06.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-611","CWE-835"],"affected":["libexpat project/libexpat","python/python","debian/debian linux"],"epss":{"score":0.08739,"percentile":0.95127,"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":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (8.74%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://www.debian.org/security/2017/dsa-3898","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2017/06/17/7","tags":["Mailing List","VDB Entry"],"source":"cve@mitre.org"},{"url":"http://www.securityfocus.com/bid/99276","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"http://www.securitytracker.com/id/1039427","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"https://github.com/libexpat/libexpat/blob/master/expat/Changes","tags":["Release Notes","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://libexpat.github.io/doc/cve-2017-9233/","tags":["Exploit","Technical Description","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E","source":"cve@mitre.org"},{"url":"https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E","source":"cve@mitre.org"},{"url":"https://support.apple.com/HT208112","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://support.apple.com/HT208113","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://support.apple.com/HT208115","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://support.apple.com/HT208144","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://support.f5.com/csp/article/K03244804","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://www.debian.org/security/2017/dsa-3898","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2017/06/17/7","tags":["Mailing List","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/99276","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1039427","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/libexpat/libexpat/blob/master/expat/Changes","tags":["Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://libexpat.github.io/doc/cve-2017-9233/","tags":["Exploit","Technical Description","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/HT208112","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/HT208113","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/HT208115","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/HT208144","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.f5.com/csp/article/K03244804","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2017-9233","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."}