{"schemaVersion":3,"id":"CVE-2026-76956","aliases":["ALPINE-CVE-2026-76956","UBUNTU-CVE-2026-76956","DEBIAN-CVE-2026-76956"],"status":"published","duplicateOf":null,"title":null,"description":"In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code leads to insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of service via crafted XML content.","dates":{"published":"2026-08-20T04:22:51.381Z","modified":"2026-08-20T17:42:38.849Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Alpine","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","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","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","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","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","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","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","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00287,"percentile":0.2003,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.00287},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00287,"percentile":0.2003}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00452,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00287,"percentile":0.2003}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-394","name":"Unexpected Status Code or Return Value","description":"The product does not properly check when a function or operation returns a value that is legitimate for the function, but is not expected by the product.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/394.html"}],"affected":[{"vendor":"alpine","product":"expat","name":"expat","label":"expat","ecosystem":"Alpine Linux","cpePart":null,"purl":"pkg:apk/alpine/expat","purlType":"apk","versions":[{"text":"< 2.8.4-r0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2.8.4-r0","eol":null,"hubHref":null},{"vendor":"debian","product":"expat","name":"expat","label":"expat","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/expat","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 2.9.0-1~deb13u1","noFixRecorded":false,"fixedIn":null},{"text":"< 2.8.4-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 2.9.0-1~deb13u1 | < 2.8.4-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"ayttm","name":"ayttm","label":"ayttm","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/ayttm","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"cableswig","name":"cableswig","label":"cableswig","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/cableswig","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"cadaver","name":"cadaver","label":"cadaver","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/cadaver","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"coin3","name":"coin3","label":"coin3","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/coin3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"gdcm","name":"gdcm","label":"gdcm","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/gdcm","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"insighttoolkit4","name":"insighttoolkit4","label":"insighttoolkit4","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/insighttoolkit4","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"libxmltok","name":"libxmltok","label":"libxmltok","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/libxmltok","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"matanza","name":"matanza","label":"matanza","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/matanza","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"smart","name":"smart","label":"smart","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/smart","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"swish-e","name":"swish-e","label":"swish-e","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/swish-e","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"tdom","name":"tdom","label":"tdom","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/tdom","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"vnc4","name":"vnc4","label":"vnc4","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/vnc4","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"vtk","name":"vtk","label":"vtk","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/vtk","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"wbxml2","name":"wbxml2","label":"wbxml2","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/wbxml2","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"xmlrpc-c","name":"xmlrpc-c","label":"xmlrpc-c","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/xmlrpc-c","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"libexpat_project","product":"libexpat","name":"libexpat","label":"libexpat","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.8.2, < 2.8.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.8.2, < 2.8.4","eol":null,"hubHref":"/vendor/libexpat_project/libexpat"}],"affectedCount":18,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/libexpat/libexpat/pull/1326","label":"github.com/libexpat/libexpat/pull/1326","hostname":"github.com","tags":["REPORT","Issue Tracking","Patch"]},{"url":"https://github.com/libexpat/libexpat/pull/1329","label":"github.com/libexpat/libexpat/pull/1329","hostname":"github.com","tags":["Issue Tracking","Patch"]},{"url":"https://security.alpinelinux.org/vuln/CVE-2026-76956","label":"security.alpinelinux.org/vuln/CVE-2026-76956","hostname":"security.alpinelinux.org","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-76956","label":"ubuntu.com/security/CVE-2026-76956","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-76956","label":"www.cve.org/CVERecord?id=CVE-2026-76956","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-76956","label":"security-tracker.debian.org/tracker/CVE-2026-76956","hostname":"security-tracker.debian.org","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76956","label":"nvd.nist.gov/vuln/detail/CVE-2026-76956","hostname":"nvd.nist.gov","tags":["Oval","Advisory"]}],"lineage":{"upstream":[],"downstream":["MGASA-2026-0378","OPENSUSE-SU-2026:11733-1","OPENSUSE-SU-2026:21945-1","RHSA-2026:60451","RHSA-2026:65568","SUSE-SU-2026:23894-1","SUSE-SU-2026:23912-1","SUSE-SU-2026:4615-1","SUSE-SU-2026:4619-1","SUSE-SU-2026:4623-1","SUSE-SU-2026:4736-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:11733-1","OPENSUSE-SU-2026:21945-1","SUSE-SU-2026:23894-1","SUSE-SU-2026:23912-1","SUSE-SU-2026:4615-1","SUSE-SU-2026:4619-1","SUSE-SU-2026:4623-1","SUSE-SU-2026:4736-1"]},"timeline":[{"kind":"published","date":"2026-08-20T04:22:51.381Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-08-20T17:42:38.849Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T03:25:06.793Z","stale":false,"partial":false}}