{"schemaVersion":3,"id":"CVE-2026-18663","aliases":["UBUNTU-CVE-2026-18663","DEBIAN-CVE-2026-18663"],"status":"published","duplicateOf":null,"title":"389-ds-base: 389-ds-base: pre-authentication double-free in get_ldapmessage_controls_ext() via critical session tracking control","description":"A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function frees the parsed controls array on the Session Tracking critical-control rejection path without clearing the SLAPI_REQCONTROLS pblock slot. Operation teardown then frees the same pointer again, causing a double-free. An unauthenticated remote attacker can trigger this with a single BIND request carrying a critical Session Tracking control, resulting in heap corruption and potential denial of service.","dates":{"published":"2026-08-12T09:35:26.681Z","modified":"2026-08-13T15:41:09.335Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":5.9,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:H/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 · Ubuntu","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":5.6,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","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":5.6,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","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}]},"epss":{"probability":0.00511,"percentile":0.42723,"severity":"low","asOf":"2026-10-22T00:00:00.000Z","change":{"pp":0.07899999999999999,"baselineDate":"2026-09-22T00:00:00.000Z","baselineScore":0.00432},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-22T00:00:00.000Z","score":0.00511,"percentile":0.42723}],"last30":[{"date":"2026-09-22T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00511,"percentile":null},{"date":"2026-10-22T00:00:00.000Z","score":0.00511,"percentile":0.42723}]},"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-415","name":"Double Free","description":"The product calls free() twice on the same memory address.","type":"weakness","status":"Draft","abstraction":"Variant","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/415.html"}],"affected":[{"vendor":"debian","product":"389-ds-base","name":"389-ds-base","label":"389-ds-base","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/389-ds-base","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"389-ds-base","name":"389-ds-base","label":"389-ds-base","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/389-ds-base","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18663","label":"access.redhat.com/security/cve/CVE-2026-18663","hostname":"access.redhat.com","tags":["VDB Entry","X Refsource REDHAT","REPORT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2510631","label":"bugzilla.redhat.com/show_bug.cgi?id=2510631","hostname":"bugzilla.redhat.com","tags":["Issue Tracking","X Refsource REDHAT","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-18663","label":"ubuntu.com/security/CVE-2026-18663","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-18663","label":"www.cve.org/CVERecord?id=CVE-2026-18663","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-18663","label":"security-tracker.debian.org/tracker/CVE-2026-18663","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:11739-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:11739-1"]},"timeline":[{"kind":"published","date":"2026-08-12T09:35:26.681Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-08-13T15:41:09.335Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":24,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T20:04:30.706Z","stale":false,"partial":false}}