{"schemaVersion":3,"id":"CVE-2026-61911","aliases":["UBUNTU-CVE-2026-61911","DEBIAN-CVE-2026-61911"],"status":"published","duplicateOf":null,"title":null,"description":"An issue was discovered in Cyrus IMAP before 3.12.4. There is a Sieve mailbox existence oracle. An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired during LMTP delivery.","dates":{"published":"2026-09-09T00:00:00.000Z","modified":"2026-09-10T19:01:53.316Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":4.3,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","exploitability":7.2,"impact":2.3,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","exploitability":7.2,"impact":2.3,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00218,"percentile":0.11554,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0.0010000000000000026,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.00217},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00373,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00373,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00218,"percentile":0.11554}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00217,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00373,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00373,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00218,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00218,"percentile":0.11554}]},"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-497","name":"Exposure of Sensitive System Information to an Unauthorized Control Sphere","description":"The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.","type":"weakness","status":"Incomplete","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/497.html"}],"affected":[{"vendor":"cyrus","product":"imap","name":"imap","label":"imap","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 3.8.8","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.9.0, < 3.10.4","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.11.0, < 3.12.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.8.8 | ≥ 3.9.0, < 3.10.4 | ≥ 3.11.0, < 3.12.4","eol":null,"hubHref":"/vendor/cyrus/imap"},{"vendor":"cyrusimap","product":"cyrus_imap","name":"cyrus imap","label":"cyrus_imap","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 3.8.8","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.9.0, < 3.10.4","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.11.0, < 3.12.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.8.8 | ≥ 3.9.0, < 3.10.4 | ≥ 3.11.0, < 3.12.4","eol":null,"hubHref":"/vendor/cyrusimap/cyrus_imap"},{"vendor":"debian","product":"cyrus-imapd","name":"cyrus-imapd","label":"cyrus-imapd","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/cyrus-imapd","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 3.12.4-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 3.12.4-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"cyrus-imapd","name":"cyrus-imapd","label":"cyrus-imapd","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/cyrus-imapd","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":4,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://cyrusimap.org","label":"cyrusimap.org","hostname":"cyrusimap.org","tags":["Product"]},{"url":"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html","label":"www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html","hostname":"www.cyrusimap.org","tags":["Release Notes"]},{"url":"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html","label":"www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html","hostname":"www.cyrusimap.org","tags":["Release Notes"]},{"url":"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html","label":"www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html","hostname":"www.cyrusimap.org","tags":["Release Notes"]},{"url":"https://ubuntu.com/security/CVE-2026-61911","label":"ubuntu.com/security/CVE-2026-61911","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-61911","label":"www.cve.org/CVERecord?id=CVE-2026-61911","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-61911","label":"security-tracker.debian.org/tracker/CVE-2026-61911","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:21929-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:21929-1"]},"timeline":[{"kind":"published","date":"2026-09-09T00:00:00.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-10T19:01:53.316Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":17,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T16:06:20.457Z","stale":false,"partial":false}}