{"id":"CVE-2021-26879","aliases":["EUVD-2021-13663","GHSA-cr47-c6rx-c855"],"status":"published","title":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","description":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.03873,"percentile":0.90341,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2021-03-11T15:41:03Z","modified":"2026-08-19T18:32:32Z","products":[{"vendor":"microsoft","product":"windows 10 version 1507"},{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1803"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 1909"},{"vendor":"microsoft","product":"windows 10 version 2004"},{"vendor":"microsoft","product":"windows 8.1"},{"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 version 2004"},{"vendor":"microsoft","product":"windows server version 20h2"},{"vendor":"microsoft","product":"windows server, version 1909 (server core installation)"},{"vendor":"microsoft","product":"windows_10"},{"vendor":"microsoft","product":"windows_8.1"},{"vendor":"microsoft","product":"windows_server_2012"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26879","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26879","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26879"},{"url":"https://github.com/advisories/GHSA-cr47-c6rx-c855"}],"sources":{"cve":[{"id":"CVE-2021-26879","title":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","description":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","status":"published","published":"2021-03-11T15:41:03Z","modified":"2026-08-19T16:30:27.825Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:32:57.368269Z"}],"euvd":[{"id":"EUVD-2021-13663","description":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","status":"published","published":"2021-03-11T15:41:03Z","modified":"2026-08-19T16:30:27Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:01:42.811156Z"}],"ghsa":[{"id":"GHSA-cr47-c6rx-c855","title":"Windows NAT Denial of Service Vulnerability","description":"Windows NAT Denial of Service Vulnerability","status":"published","published":"2022-05-24T17:44:20Z","modified":"2026-08-19T18:32:32Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:10:42.300371Z"}],"nvd":[{"id":"CVE-2021-26879","description":"Windows Network Address Translation (NAT) Denial of Service Vulnerability","status":"published","published":"2021-03-11T16:15:15.333Z","modified":"2026-08-19T17:17:43.44Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:06:50.805771Z"}]}}