{"history":[{"alert":0,"cve":"CVE-2021-31166","id":22211,"kind":"epss","observed_at":1794500401,"payload":"{\"date\": \"2026-11-12\", \"epss\": 0.99867, \"percentile\": 0.99963}"},{"alert":0,"cve":"CVE-2021-31166","id":19830,"kind":"epss","observed_at":1794327601,"payload":"{\"date\": \"2026-11-10\", \"epss\": 0.99867, \"percentile\": 0.99963}"},{"alert":0,"cve":"CVE-2021-31166","id":17796,"kind":"epss","observed_at":1794241201,"payload":"{\"date\": \"2026-11-09\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":0,"cve":"CVE-2021-31166","id":15860,"kind":"epss","observed_at":1794154800,"payload":"{\"date\": \"2026-11-08\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":0,"cve":"CVE-2021-31166","id":13838,"kind":"epss","observed_at":1794068402,"payload":"{\"date\": \"2026-11-07\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":0,"cve":"CVE-2021-31166","id":11620,"kind":"epss","observed_at":1793982001,"payload":"{\"date\": \"2026-11-06\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":0,"cve":"CVE-2021-31166","id":9606,"kind":"epss","observed_at":1793938800,"payload":"{\"date\": \"2026-11-05\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":1,"cve":"CVE-2021-31166","id":8458,"kind":"cna","observed_at":1793874000,"payload":"{\"containers\": {\"adp\": [{\"providerMetadata\": {\"dateUpdated\": \"2024-08-03T22:55:52.129Z\", \"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\"}, \"references\": [{\"tags\": [\"x_refsource_MISC\", \"x_transferred\"], \"url\": \"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166\"}, {\"tags\": [\"x_refsource_MISC\", \"x_transferred\"], \"url\": \"http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html\"}], \"title\": \"CVE Program Container\"}, {\"metrics\": [{\"other\": {\"content\": {\"id\": \"CVE-2021-31166\", \"options\": [{\"Exploitation\": \"active\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"role\": \"CISA Coordinator\", \"timestamp\": \"2025-02-07T14:36:57.411562Z\", \"version\": \"2.0.3\"}, \"type\": \"ssvc\"}}, {\"other\": {\"content\": {\"dateAdded\": \"2022-04-06\", \"reference\": \"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166\"}, \"type\": \"kev\"}}], \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-416\", \"description\": \"CWE-416 Use After Free\", \"lang\": \"en\", \"type\": \"CWE\"}]}], \"providerMetadata\": {\"dateUpdated\": \"2025-10-21T23:25:45.988Z\", \"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\"}, \"references\": [{\"tags\": [\"government-resource\"], \"url\": \"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2022-04-06T00:00:00.000Z\", \"value\": \"CVE-2021-31166 added to CISA KEV\"}], \"title\": \"CISA ADP Vulnrichment\"}], \"cna\": {\"affected\": [{\"cpes\": [\"cpe:2.3:o:microsoft:windows_10_1809:10.0.19041.982:*:*:*:*:*:x64:*\"], \"platforms\": [\"32-bit Systems\", \"ARM64-based Systems\", \"x64-based Systems\"], \"product\": \"Windows 10 Version 2004\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"10.0.19041.982\", \"status\": \"affected\", \"version\": \"10.0.0\", \"versionType\": \"custom\"}]}, {\"cpes\": [\"cpe:2.3:o:microsoft:windows_server_2004:10.0.19041.982:*:*:*:*:*:*:*\"], \"platforms\": [\"x64-based Systems\"], \"product\": \"Windows Server version 2004\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"10.0.19041.982\", \"status\": \"affected\", \"version\": \"10.0.0\", \"versionType\": \"custom\"}]}, {\"cpes\": [\"cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:x86:*\", \"cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:arm64:*\"], \"platforms\": [\"32-bit Systems\", \"ARM64-based Systems\"], \"product\": \"Windows 10 Version 20H2\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"10.0.19042.982\", \"status\": \"affected\", \"version\": \"10.0.0\", \"versionType\": \"custom\"}]}, {\"cpes\": [\"cpe:2.3:o:microsoft:windows_server_20H2:10.0.19042.982:*:*:*:*:*:*:*\"], \"platforms\": [\"x64-based Systems\"], \"product\": \"Windows Server version 20H2\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"10.0.19042.982\", \"status\": \"affected\", \"version\": \"10.0.0\", \"versionType\": \"custom\"}]}], \"datePublic\": \"2021-05-11T07:00:00.000Z\", \"descriptions\": [{\"lang\": \"en-US\", \"value\": \"HTTP Protocol Stack Remote Code Execution Vulnerability\"}], \"metrics\": [{\"cvssV3_1\": {\"baseScore\": 9.8, \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C\", \"version\": \"3.1\"}, \"format\": \"CVSS\", \"scenarios\": [{\"lang\": \"en-US\", \"value\": \"GENERAL\"}]}], \"problemTypes\": [{\"descriptions\": [{\"description\": \"Remote Code Execution\", \"lang\": \"en-US\", \"type\": \"Impact\"}]}], \"providerMetadata\": {\"dateUpdated\": \"2023-12-28T23:56:49.266Z\", \"orgId\": \"f38d906d-7342-40ea-92c1-6c4a2c6478c8\", \"shortName\": \"microsoft\"}, \"references\": [{\"tags\": [\"x_refsource_MISC\"], \"url\": \"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166\"}, {\"tags\": [\"x_refsource_MISC\"], \"url\": \"http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html\"}], \"title\": \"HTTP Protocol Stack Remote Code Execution Vulnerability\"}}, \"cveMetadata\": {\"assignerOrgId\": \"f38d906d-7342-40ea-92c1-6c4a2c6478c8\", \"assignerShortName\": \"microsoft\", \"cveId\": \"CVE-2021-31166\", \"datePublished\": \"2021-05-11T19:11:19.000Z\", \"dateReserved\": \"2021-04-14T00:00:00.000Z\", \"dateUpdated\": \"2025-10-21T23:25:45.988Z\", \"state\": \"PUBLISHED\"}, \"dataType\": \"CVE_RECORD\", \"dataVersion\": \"5.1\"}"},{"alert":0,"cve":"CVE-2021-31166","id":7154,"kind":"epss","observed_at":1793809200,"payload":"{\"date\": \"2026-11-04\", \"epss\": 0.99867, \"percentile\": 0.99962}"},{"alert":0,"cve":"CVE-2021-31166","id":4931,"kind":"epss","observed_at":1793722800,"payload":"{\"date\": \"2026-11-03\", \"epss\": 0.99867, \"percentile\": 0.99963}"},{"alert":0,"cve":"CVE-2021-31166","id":2713,"kind":"epss","observed_at":1793665375,"payload":"{\"date\": \"2026-11-02\", \"epss\": 0.99867, \"percentile\": 0.99963}"},{"alert":1,"cve":"CVE-2021-31166","id":1152,"kind":"kev","observed_at":1793665375,"payload":"{\"cveID\": \"CVE-2021-31166\", \"cwes\": [\"CWE-416\"], \"dateAdded\": \"2022-04-06\", \"dueDate\": \"2022-04-27\", \"forensicTriage\": \"No\", \"knownRansomwareCampaignUse\": \"Unknown\", \"notes\": \"https://nvd.nist.gov/vuln/detail/CVE-2021-31166\", \"product\": \"HTTP Protocol Stack\", \"requiredAction\": \"Apply updates per vendor instructions.\", \"shortDescription\": \"Microsoft HTTP Protocol Stack contains a vulnerability in http.sys that allows for remote code execution.\", \"vendorProject\": \"Microsoft\", \"vulnerabilityName\": \"Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability\"}"}],"record":{"affected":[{"cpes":["cpe:2.3:o:microsoft:windows_10_1809:10.0.19041.982:*:*:*:*:*:x64:*"],"platforms":["32-bit Systems","ARM64-based Systems","x64-based Systems"],"product":"Windows 10 Version 2004","vendor":"Microsoft","versions":[{"lessThan":"10.0.19041.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_server_2004:10.0.19041.982:*:*:*:*:*:*:*"],"platforms":["x64-based Systems"],"product":"Windows Server version 2004","vendor":"Microsoft","versions":[{"lessThan":"10.0.19041.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:x86:*","cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:arm64:*"],"platforms":["32-bit Systems","ARM64-based Systems"],"product":"Windows 10 Version 20H2","vendor":"Microsoft","versions":[{"lessThan":"10.0.19042.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_server_20H2:10.0.19042.982:*:*:*:*:*:*:*"],"platforms":["x64-based Systems"],"product":"Windows Server version 20H2","vendor":"Microsoft","versions":[{"lessThan":"10.0.19042.982","status":"affected","version":"10.0.0","versionType":"custom"}]}],"cna":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2024-08-03T22:55:52.129Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"tags":["x_refsource_MISC","x_transferred"],"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166"},{"tags":["x_refsource_MISC","x_transferred"],"url":"http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html"}],"title":"CVE Program Container"},{"metrics":[{"other":{"content":{"id":"CVE-2021-31166","options":[{"Exploitation":"active"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2025-02-07T14:36:57.411562Z","version":"2.0.3"},"type":"ssvc"}},{"other":{"content":{"dateAdded":"2022-04-06","reference":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166"},"type":"kev"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","description":"CWE-416 Use After Free","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2025-10-21T23:25:45.988Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"references":[{"tags":["government-resource"],"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166"}],"timeline":[{"lang":"en","time":"2022-04-06T00:00:00.000Z","value":"CVE-2021-31166 added to CISA KEV"}],"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"cpes":["cpe:2.3:o:microsoft:windows_10_1809:10.0.19041.982:*:*:*:*:*:x64:*"],"platforms":["32-bit Systems","ARM64-based Systems","x64-based Systems"],"product":"Windows 10 Version 2004","vendor":"Microsoft","versions":[{"lessThan":"10.0.19041.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_server_2004:10.0.19041.982:*:*:*:*:*:*:*"],"platforms":["x64-based Systems"],"product":"Windows Server version 2004","vendor":"Microsoft","versions":[{"lessThan":"10.0.19041.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:x86:*","cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.982:*:*:*:*:*:arm64:*"],"platforms":["32-bit Systems","ARM64-based Systems"],"product":"Windows 10 Version 20H2","vendor":"Microsoft","versions":[{"lessThan":"10.0.19042.982","status":"affected","version":"10.0.0","versionType":"custom"}]},{"cpes":["cpe:2.3:o:microsoft:windows_server_20H2:10.0.19042.982:*:*:*:*:*:*:*"],"platforms":["x64-based Systems"],"product":"Windows Server version 20H2","vendor":"Microsoft","versions":[{"lessThan":"10.0.19042.982","status":"affected","version":"10.0.0","versionType":"custom"}]}],"datePublic":"2021-05-11T07:00:00.000Z","descriptions":[{"lang":"en-US","value":"HTTP Protocol Stack Remote Code Execution Vulnerability"}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en-US","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"description":"Remote Code Execution","lang":"en-US","type":"Impact"}]}],"providerMetadata":{"dateUpdated":"2023-12-28T23:56:49.266Z","orgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","shortName":"microsoft"},"references":[{"tags":["x_refsource_MISC"],"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166"},{"tags":["x_refsource_MISC"],"url":"http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html"}],"title":"HTTP Protocol Stack Remote Code Execution Vulnerability"}},"cveMetadata":{"assignerOrgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","assignerShortName":"microsoft","cveId":"CVE-2021-31166","datePublished":"2021-05-11T19:11:19.000Z","dateReserved":"2021-04-14T00:00:00.000Z","dateUpdated":"2025-10-21T23:25:45.988Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.1"},"cna_checked":1794349204,"cve":"CVE-2021-31166","description":"HTTP Protocol Stack Remote Code Execution Vulnerability","epss":{"date":"2026-11-12","epss":0.99867,"percentile":0.99963},"epss_checked":1794522003,"first_seen":1793665375,"kev":{"cveID":"CVE-2021-31166","cwes":["CWE-416"],"dateAdded":"2022-04-06","dueDate":"2022-04-27","forensicTriage":"No","knownRansomwareCampaignUse":"Unknown","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-31166","product":"HTTP Protocol Stack","requiredAction":"Apply updates per vendor instructions.","shortDescription":"Microsoft HTTP Protocol Stack contains a vulnerability in http.sys that allows for remote code execution.","vendorProject":"Microsoft","vulnerabilityName":"Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability"},"kev_checked":1794522003,"products":"Microsoft Windows 10 Version 2004, Microsoft Windows Server version 2004, Microsoft Windows 10 Version 20H2, Microsoft Windows Server version 20H2","references":["https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166","http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html","https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166"],"score":{"baseScore":9.8,"baseSeverity":"CRITICAL","provider":"microsoft","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","version":"3.1"},"solutions":"","state":"PUBLISHED","title":"HTTP Protocol Stack Remote Code Execution Vulnerability","updated_at":1794500401,"workarounds":""},"sources":[]}