{"id":"CVE-2026-20839","aliases":["EUVD-2026-2162","GHSA-gwv7-x72m-q3cm"],"status":"published","title":"Windows Client-Side Caching (CSC) Service Information Disclosure Vulnerability","description":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00476,"percentile":0.41615,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-284"],"published":"2026-01-13T17:56:26Z","modified":"2026-07-30T21:17:01Z","products":[{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 21h2"},{"vendor":"microsoft","product":"windows 10 version 22h2"},{"vendor":"microsoft","product":"windows 11 version 23h2"},{"vendor":"microsoft","product":"windows 11 version 24h2"},{"vendor":"microsoft","product":"windows 11 version 25h2"},{"vendor":"microsoft","product":"windows server 2008 r2 service pack 1"},{"vendor":"microsoft","product":"windows server 2008 r2 service pack 1 (server core installation)"},{"vendor":"microsoft","product":"windows server 2012"},{"vendor":"microsoft","product":"windows server 2012 (server core installation)"},{"vendor":"microsoft","product":"windows server 2012 r2"},{"vendor":"microsoft","product":"windows server 2012 r2 (server core installation)"},{"vendor":"microsoft","product":"windows server 2016"},{"vendor":"microsoft","product":"windows server 2016 (server core installation)"},{"vendor":"microsoft","product":"windows server 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"vendor":"microsoft","product":"windows server 2022"},{"vendor":"microsoft","product":"windows server 2022, 23h2 edition (server core installation)"},{"vendor":"microsoft","product":"windows server 2025"},{"vendor":"microsoft","product":"windows server 2025 (server core installation)"},{"vendor":"microsoft","product":"windows_10_1607"},{"vendor":"microsoft","product":"windows_10_1809"},{"vendor":"microsoft","product":"windows_10_21h2"},{"vendor":"microsoft","product":"windows_10_22h2"},{"vendor":"microsoft","product":"windows_11_23h2"},{"vendor":"microsoft","product":"windows_11_24h2"},{"vendor":"microsoft","product":"windows_11_25h2"},{"vendor":"microsoft","product":"windows_server_2008"},{"vendor":"microsoft","product":"windows_server_2012"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"},{"vendor":"microsoft","product":"windows_server_2022"},{"vendor":"microsoft","product":"windows_server_2022_23h2"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20839","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20839"},{"url":"https://github.com/advisories/GHSA-gwv7-x72m-q3cm"}],"sources":{"cve":[{"id":"CVE-2026-20839","title":"Windows Client-Side Caching (CSC) Service Information Disclosure Vulnerability","description":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.","status":"published","published":"2026-01-13T17:56:26.609Z","modified":"2026-07-30T20:46:43.518Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T13:35:44.571002Z"}],"euvd":[{"id":"EUVD-2026-2162","description":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.","status":"published","published":"2026-01-13T17:56:26Z","modified":"2026-07-30T20:46:43Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T18:02:27.233735Z"}],"ghsa":[{"id":"GHSA-gwv7-x72m-q3cm","title":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized...","description":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.","status":"published","published":"2026-01-13T18:31:09Z","modified":"2026-01-13T18:31:14Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T15:05:34.558577Z"}],"nvd":[{"id":"CVE-2026-20839","description":"Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.","status":"published","published":"2026-01-13T18:16:12.32Z","modified":"2026-07-30T21:17:01.867Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T14:12:03.683495Z"}]}}