CVE-2026-27858

{"id": "CVE-2026-27858", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-27858", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-27T12:36:26.526829Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@open-xchange.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}, {"type": "Secondary", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@open-xchange.com", "affectedData": [{"vendor": "Open-Xchange GmbH", "modules": ["core"], "product": "OX Dovecot Pro", "versions": [{"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "2.3.0"}, {"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "3.1.0"}, {"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "2.4.0"}], "defaultStatus": "unaffected"}]}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "affectedData": [{"cpes": ["cpe:/o:redhat:enterprise_linux:10.1", "cpe:/o:redhat:enterprise_linux:10.2"], "vendor": "Red Hat", "product": "Red 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"rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "versions": [{"status": "unaffected", "version": "1:2.3.16-7.el8_10", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_aus:8.4"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support", "versions": [{"status": "unaffected", "version": "1:2.3.8-9.el8_4.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_eus_long_life:8.4"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On", "versions": [{"status": "unaffected", "version": "1:2.3.8-9.el8_4.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_aus:8.6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support", "versions": [{"status": "unaffected", "version": "1:2.3.16-2.el8_6.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_tus:8.6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.6 Telecommunications Update Service", "versions": [{"status": "unaffected", "version": "1:2.3.16-2.el8_6.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:8.6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "1:2.3.16-2.el8_6.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_tus:8.8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.8 Telecommunications Update Service", "versions": [{"status": "unaffected", "version": "1:2.3.16-3.el8_8.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:8.8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "1:2.3.16-3.el8_8.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:9"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "versions": [{"status": "unaffected", "version": "1:2.3.16-15.el9_7.1", "lessThan": "*", "versionType": "rpm"}, {"status": "unaffected", "version": "1:2.3.16-18.el9_8", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:9.0"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "1:2.3.16-3.el9_0.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:9.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "1:2.3.16-8.el9_2.2", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_eus:9.4"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.4 Extended Update Support", "versions": [{"status": "unaffected", "version": "1:2.3.16-11.el9_4.2", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_eus:9.6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.6 Extended Update Support", "versions": [{"status": "unaffected", "version": "1:2.3.16-15.el9_6.1", "lessThan": "*", "versionType": "rpm"}], "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "packageName": "dovecot", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}]}], "published": "2026-03-27T09:16:20.073", "references": [{"url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json", "tags": ["Vendor Advisory"], "source": "security@open-xchange.com"}, {"url": "https://access.redhat.com/errata/RHSA-2026:13498", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:13830", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:13857", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17602", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17625", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17626", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17628", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17630", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:18053", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:19149", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:19364", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:19453", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:19455", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/errata/RHSA-2026:26564", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://access.redhat.com/security/cve/CVE-2026-27858", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2452175", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27858.json", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "security@open-xchange.com", "description": [{"lang": "en", "value": "CWE-400"}]}, {"type": "Secondary", "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "description": [{"lang": "en", "value": "CWE-770"}]}], "descriptions": [{"lang": "en", "value": "Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory.\r\n Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known."}], "lastModified": "2026-07-15T02:19:11.340", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BE209329-C5EA-4EE7-A23E-CD2EC061A9A4", "versionEndExcluding": "2.4.3"}, {"criteria": "cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*", "vulnerable": true, "matchCriteriaId": "5CF82590-D98A-4E06-AC8C-6CC3506ED923", "versionEndExcluding": "2.3.22.1"}, {"criteria": "cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*", "vulnerable": true, "matchCriteriaId": "8476287B-40B2-4533-A3AB-B880516C0B5C", "versionEndExcluding": "3.0.5", "versionStartIncluding": "3.0.0"}, {"criteria": "cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*", "vulnerable": true, "matchCriteriaId": "11CA35AA-72CB-4614-A064-8A90F65D8A71", "versionEndExcluding": "3.1.4", "versionStartIncluding": "3.1.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@open-xchange.com"}