{"schemaVersion":3,"id":"CVE-2026-42008","aliases":["UBUNTU-CVE-2026-42008","DEBIAN-CVE-2026-42008"],"status":"published","duplicateOf":null,"title":null,"description":"Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.","dates":{"published":"2026-08-28T10:12:26.018Z","modified":"2026-08-28T15:54:17.203Z","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:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00236,"percentile":0.13723,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0.043000000000000003,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.00193},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00236,"percentile":0.13723}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00193,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00263,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00236,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00236,"percentile":0.13723}]},"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-287","name":"Improper Authentication","description":"When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/287.html"}],"affected":[{"vendor":"debian","product":"dovecot","name":"dovecot","label":"dovecot","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/dovecot","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 1:2.4.1+dfsg1-6+deb13u7","noFixRecorded":false,"fixedIn":null},{"text":"< 1:2.4.5+dfsg1-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 1:2.4.1+dfsg1-6+deb13u7 | < 1:2.4.5+dfsg1-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"dovecot","name":"dovecot","label":"dovecot","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/dovecot","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"open-xchange gmbh","product":"ox dovecot ce","name":"OX Dovecot CE","label":"ox dovecot ce","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.3.4, < 2.4.5","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.3.4, < 2.4.5","eol":null,"hubHref":"/vendor/open-xchange_gmbh/ox_dovecot_ce"},{"vendor":"open-xchange gmbh","product":"ox dovecot pro","name":"OX Dovecot Pro","label":"ox dovecot pro","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.3.4, < 2.3.22.2","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.0.0, < 3.0.7","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.1.0, < 3.1.6","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.3.4, < 2.3.22.2 | ≥ 3.0.0, < 3.0.7 | ≥ 3.1.0, < 3.1.6","eol":null,"hubHref":"/vendor/open-xchange_gmbh/ox_dovecot_pro"}],"affectedCount":4,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json","label":"documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json","hostname":"documentation.open-xchange.com","tags":["Vendor Advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-42008","label":"ubuntu.com/security/CVE-2026-42008","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-42008","label":"www.cve.org/CVERecord?id=CVE-2026-42008","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-42008","label":"security-tracker.debian.org/tracker/CVE-2026-42008","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["MGASA-2026-0385","OPENSUSE-SU-2026:21720-1","SUSE-SU-2026:23595-1","SUSE-SU-2026:4139-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:21720-1","SUSE-SU-2026:23595-1","SUSE-SU-2026:4139-1"]},"timeline":[{"kind":"published","date":"2026-08-28T10:12:26.018Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-08-28T15:54:17.203Z","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":"2026-10-21T23:50:17.132Z","stale":false,"partial":false}}