{"id":"CVE-2021-26564","aliases":["EUVD-2021-13362","GHSA-77r2-rjfh-m7wh"],"status":"published","title":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology...","description":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to spoof servers via an HTTP session.","severity":{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00668,"percentile":0.52403,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-319"],"published":"2021-02-26T21:45:33Z","modified":"2026-06-17T03:43:29Z","products":[{"vendor":"synology","product":"diskstation_manager"},{"vendor":"synology","product":"diskstation_manager_unified_controller"},{"vendor":"synology","product":"skynas_firmware"},{"vendor":"synology","product":"synology diskstation manager (dsm)"},{"vendor":"synology","product":"vs960hd_firmware"}],"references":[{"url":"https://www.synology.com/security/advisory/Synology_SA_20_26","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1160","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26564"},{"url":"https://github.com/advisories/GHSA-77r2-rjfh-m7wh"}],"sources":{"cve":[{"id":"CVE-2021-26564","description":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to spoof servers via an HTTP session.","status":"published","published":"2021-02-26T21:45:33.663Z","modified":"2024-09-17T00:46:03.051Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-319"],"updated_at":"2026-11-02T14:32:57.033395Z"}],"euvd":[{"id":"EUVD-2021-13362","description":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to spoof servers via an HTTP session.","status":"published","published":"2021-02-26T21:45:33Z","modified":"2024-09-17T00:46:03Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T00:28:55.842484Z"}],"ghsa":[{"id":"GHSA-77r2-rjfh-m7wh","title":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology...","description":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to spoof servers via an HTTP session.","status":"published","published":"2022-05-24T17:43:19Z","modified":"2023-01-29T05:05:32Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-319"],"updated_at":"2026-11-02T14:45:48.864861Z"}],"nvd":[{"id":"CVE-2021-26564","description":"Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to spoof servers via an HTTP session.","status":"published","published":"2021-02-26T22:15:20.3Z","modified":"2026-06-17T03:43:29.163Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-319"],"updated_at":"2026-11-02T14:06:50.399901Z"}]}}