{"id":"CVE-2026-40013","state":"PUBLISHED","title":"An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles th","description":"An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.","publishedAt":"2026-08-28T10:12:16.751Z","updatedAt":"2026-08-28T15:54:38.082Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","source":"OX"},"assigner":"OX","products":["Open-Xchange GmbH OX Dovecot Pro","Open-Xchange GmbH OX Dovecot CE"],"affected":[{"vendor":"Open-Xchange GmbH","product":"OX Dovecot Pro","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"2.3.22.2","versionType":"semver"},{"version":"3.0.0","status":"affected","lessThan":"3.0.7","versionType":"semver"},{"version":"3.1.0","status":"affected","lessThan":"3.1.6","versionType":"semver"}],"modules":["core"]},{"vendor":"Open-Xchange GmbH","product":"OX Dovecot CE","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"2.4.5","versionType":"semver"}],"modules":["core"]}],"references":["https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json"],"weaknesses":["CWE-124"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40013.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40013","state":"PUBLISHED","datePublished":"2026-08-28T10:12:16.751Z","dateUpdated":"2026-08-28T15:54:38.082Z","assignerShortName":"OX","assignerOrgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","dateReserved":"2026-04-08T09:59:59.342Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known."}],"affected":[{"vendor":"Open-Xchange GmbH","product":"OX Dovecot Pro","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"2.3.22.2","versionType":"semver"},{"version":"3.0.0","status":"affected","lessThan":"3.0.7","versionType":"semver"},{"version":"3.1.0","status":"affected","lessThan":"3.1.6","versionType":"semver"}],"modules":["core"]},{"vendor":"Open-Xchange GmbH","product":"OX Dovecot CE","defaultStatus":"unaffected","versions":[{"version":"2.3.0","status":"affected","lessThan":"2.4.5","versionType":"semver"}],"modules":["core"]}],"references":[{"url":"https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json","tags":["vendor-advisory"]}],"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-124","description":"Buffer Underwrite ('Buffer Underflow')","lang":"en","type":"cwe"}]}],"providerMetadata":{"shortName":"OX","orgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","dateUpdated":"2026-08-28T10:30:39.263Z"},"source":{"defect":"DOV-8991","discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-28T14:32:42.229438Z","id":"CVE-2026-40013","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-28T15:54:38.082Z"}}]}}}