{"id":"CVE-2026-27856","state":"PUBLISHED","title":"Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Figuring ou","description":"Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Figuring out the credential will lead into full access to the affected component. Limit access to the doveadm http service port, install fixed version. 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An attacker can use this to determine the configured credentials. Figuring out the credential will lead into full access to the affected component. Limit access to the doveadm http service port, install fixed version. No publicly available exploits are known."}],"affected":[{"vendor":"Open-Xchange GmbH","product":"OX Dovecot Pro","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.3.0","versionType":"semver"}],"modules":["core"]}],"references":[{"url":"https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","description":"Improper Authentication","lang":"en","type":"cwe"}]}],"providerMetadata":{"shortName":"OX","orgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","dateUpdated":"2026-03-27T12:33:28.219Z"},"source":{"defect":"DOV-8830","discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-27T13:21:44.110751Z","id":"CVE-2026-27856","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-27T13:45:12.231Z"}},{"title":"dovecot: Doveadm: Full access via timing oracle attack in credential verification","descriptions":[{"lang":"en","value":"A flaw was found in Doveadm, a component of Dovecot. An attacker can exploit a timing oracle vulnerability during the direct comparison of credentials. This allows the attacker to determine the configured credentials, potentially leading to full unauthorized access to the affected component."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7 Extended Lifecycle Support","packageName":"dovecot","defaultStatus":"affected","versions":[{"version":"1:2.2.36-8.el7_9.1","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:rhel_els:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"dovecot","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","packageName":"dovecot","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"dovecot","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"dovecot","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-27856","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2452171","name":"RHBZ#2452171","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.json","tags":["x_sadp-csaf-vex"]},{"url":"https://access.redhat.com/errata/RHSA-2026:26564","tags":["vendor-advisory","x_refsource_REDHAT"]}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-208","description":"Observable Timing Discrepancy","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat-SADP","orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","dateUpdated":"2026-07-15T01:12:50.777Z"},"datePublic":"2026-03-27T08:10:19.537Z","solutions":[{"lang":"en","value":"RHSA-2026:26564: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS)"}],"timeline":[{"lang":"en","time":"2026-03-27T09:01:28.297Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-03-27T08:10:19.537Z","value":"Made public."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"}}]}}}