{"id":"CVE-2020-1118","aliases":["EUVD-2020-12005","GHSA-jgvh-pmp6-rc4h"],"status":"published","title":"Microsoft Windows Transport Layer Security Denial of Service Vulnerability","description":"A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding.\nTo exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot.\nThe update addresses the vulnerability by changing the way TLS key exchange messages are validated.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.15153,"percentile":0.96771,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2020-05-21T22:53:14Z","modified":"2026-08-19T18:32:27Z","products":[{"vendor":"microsoft","product":"windows 10 version 1709"},{"vendor":"microsoft","product":"windows 10 version 1709 for 32-bit systems"},{"vendor":"microsoft","product":"windows 10 version 1803"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 1903 for 32-bit systems"},{"vendor":"microsoft","product":"windows 10 version 1903 for arm64-based systems"},{"vendor":"microsoft","product":"windows 10 version 1903 for x64-based systems"},{"vendor":"microsoft","product":"windows 10 version 1909"},{"vendor":"microsoft","product":"windows server 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"vendor":"microsoft","product":"windows server, version 1803  (server core installation)"},{"vendor":"microsoft","product":"windows server, version 1903 (server core installation)"},{"vendor":"microsoft","product":"windows server, version 1909 (server core installation)"},{"vendor":"microsoft","product":"windows_10"},{"vendor":"microsoft","product":"windows_server_2019"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1118","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1118","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-1118"},{"url":"https://github.com/advisories/GHSA-jgvh-pmp6-rc4h"}],"sources":{"cve":[{"id":"CVE-2020-1118","title":"Microsoft Windows Transport Layer Security Denial of Service Vulnerability","description":"A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding.\nTo exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot.\nThe update addresses the vulnerability by changing the way TLS key exchange messages are validated.","status":"published","published":"2020-05-21T22:53:14Z","modified":"2026-08-19T16:33:39.283Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:35:56.638833Z"}],"euvd":[{"id":"EUVD-2020-12005","description":"A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding.\nTo exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot.\nThe update addresses the vulnerability by changing the way TLS key exchange messages are validated.","status":"published","published":"2020-05-21T22:53:14Z","modified":"2026-08-19T16:33:39Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:01:41.904829Z"}],"ghsa":[{"id":"GHSA-jgvh-pmp6-rc4h","title":"A denial of service vulnerability exists in the Windows implementation of Transport Layer...","description":"A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges, aka 'Microsoft Windows Transport Layer Security Denial of Service Vulnerability'.","status":"published","published":"2022-05-24T17:18:29Z","modified":"2026-08-19T18:32:27Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:10:41.712997Z"}],"nvd":[{"id":"CVE-2020-1118","description":"A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding.\nTo exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot.\nThe update addresses the vulnerability by changing the way TLS key exchange messages are validated.","status":"published","published":"2020-05-21T23:15:15.46Z","modified":"2026-08-19T17:17:20.22Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"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":7.8,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:06:04.922138Z"}]}}