{"id":"CVE-2026-40539","state":"PUBLISHED","title":"An improper certificate validation vulnerability in Email API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows man-in-the-middle ","description":"An improper certificate validation vulnerability in Email API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows man-in-the-middle attackers to read or write arbitrary files and conduct denial-of-service attacks.","publishedAt":"2026-09-18T08:29:33.365Z","updatedAt":"2026-09-18T10:40:16.842Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"synology"},"assigner":"synology","products":["Synology DiskStation Manager (DSM)"],"affected":[{"vendor":"Synology","product":"DiskStation Manager (DSM)","defaultStatus":"affected","versions":[{"version":"7.3","status":"affected","lessThan":"7.3.2-86009-2","versionType":"semver"},{"version":"7.2.2","status":"affected","lessThan":"7.2.2-72806-7","versionType":"semver"},{"version":"7.2.1","status":"affected","lessThan":"7.2.1-69057-10","versionType":"semver"},{"version":"0","status":"unknown","lessThan":"7.2.1","versionType":"semver"}]}],"references":["https://www.synology.com/en-global/security/advisory/Synology_SA_26_06"],"weaknesses":["CWE-295"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40539.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40539","state":"PUBLISHED","datePublished":"2026-09-18T08:29:33.365Z","dateUpdated":"2026-09-18T10:40:16.842Z","assignerShortName":"synology","assignerOrgId":"db201096-a0cc-46c7-9a55-61d9e221bf01","dateReserved":"2026-04-14T01:01:14.607Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"An improper certificate validation vulnerability in Email API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows man-in-the-middle attackers to read or write arbitrary files and conduct denial-of-service attacks."}],"affected":[{"vendor":"Synology","product":"DiskStation Manager (DSM)","defaultStatus":"affected","versions":[{"version":"7.3","status":"affected","lessThan":"7.3.2-86009-2","versionType":"semver"},{"version":"7.2.2","status":"affected","lessThan":"7.2.2-72806-7","versionType":"semver"},{"version":"7.2.1","status":"affected","lessThan":"7.2.1-69057-10","versionType":"semver"},{"version":"0","status":"unknown","lessThan":"7.2.1","versionType":"semver"}]}],"references":[{"url":"https://www.synology.com/en-global/security/advisory/Synology_SA_26_06","name":"Synology-SA-26:06 DSM","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","attackVector":"ADJACENT_NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-295","lang":"en","description":"Improper Certificate Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"synology","orgId":"db201096-a0cc-46c7-9a55-61d9e221bf01","dateUpdated":"2026-09-18T08:29:33.365Z"},"credits":[{"lang":"en","value":"Ben R of Interrupt Labs (https://www.interruptlabs.co.uk)","type":"finder"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T10:39:51.196824Z","id":"CVE-2026-40539","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":"2026-09-18T10:40:16.842Z"}}]}}}