{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27857","assignerOrgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","state":"PUBLISHED","assignerShortName":"OX","dateReserved":"2026-02-24T08:46:09.373Z","datePublished":"2026-03-27T08:10:20.761Z","dateUpdated":"2026-06-30T12:08:04.415Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","modules":["core"],"product":"OX Dovecot Pro","vendor":"Open-Xchange GmbH","versions":[{"lessThanOrEqual":"2.3.0","status":"affected","version":"0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"Sending \"NOOP (((...)))\" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Install fixed version, there is no other remediation. No publicly available exploits are known."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","description":"Uncontrolled Resource Consumption","lang":"en","type":"cwe"}]}],"providerMetadata":{"orgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","shortName":"OX","dateUpdated":"2026-03-27T12:33:29.627Z"},"references":[{"tags":["vendor-advisory"],"url":"https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json"}],"source":{"defect":"DOV-8816","discovery":"EXTERNAL"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-27T12:39:00.311649Z","id":"CVE-2026-27857","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-27T12:39:48.150Z"}},{"affected":[{"cpes":["cpe:/o:redhat:rhel_els:7"],"defaultStatus":"affected","product":"Red Hat Enterprise Linux Server (v. 7 ELS)","vendor":"Red 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An unauthenticated and remote attacker can send a specially crafted \"NOOP\" command containing numerous open and close parentheses without a command-ending line feed, causing the server to allocate an excessive amount of memory, resulting in a denial of service."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"Allocation of Resources Without Limits or 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Please update the affected package as soon as possible."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"},"providerMetadata":{"orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","shortName":"redhat-SADP","dateUpdated":"2026-06-30T12:08:04.415Z"}}]}}