{"id":"CVE-2021-31955","aliases":["EUVD-2021-18828","GHSA-4grg-84cr-6c2h"],"status":"published","title":"Windows Kernel Information Disclosure Vulnerability","description":"Windows Kernel Information Disclosure Vulnerability","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:F/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.81107,"percentile":0.9964,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":true,"fix_available":false},"cwes":["CWE-200","CWE-497"],"published":"2021-06-08T22:46:25Z","modified":"2026-06-17T03:52:33Z","kev":{"date_added":"2021-11-03","due_date":"2021-11-17","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2021-11-03"},{"source":"kev","since":"2021-11-03"}],"exploits":[{"source":"pocgithub","id":"freeide/CVE-2021-31955-POC","title":"freeide/CVE-2021-31955-POC","date":"2021-06-26","url":"https://github.com/freeide/CVE-2021-31955-POC"},{"source":"pocgithub","id":"ApexPredator-InfoSec/forti_shield","title":"ApexPredator-InfoSec/forti_shield","date":"2025-10-29","url":"https://github.com/ApexPredator-InfoSec/forti_shield"}],"products":[{"vendor":"microsoft","product":"windows"},{"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 10 version 20h2"},{"vendor":"microsoft","product":"windows 10 version 21h1"},{"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_10_1809"},{"vendor":"microsoft","product":"windows_10_1909"},{"vendor":"microsoft","product":"windows_10_2004"},{"vendor":"microsoft","product":"windows_10_20h2"},{"vendor":"microsoft","product":"windows_10_21h1"},{"vendor":"microsoft","product":"windows_server_2004"},{"vendor":"microsoft","product":"windows_server_2019"},{"vendor":"microsoft","product":"windows_server_20h2"}],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31955","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31955","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31955"},{"url":"https://github.com/advisories/GHSA-4grg-84cr-6c2h"}],"sources":{"cve":[{"id":"CVE-2021-31955","title":"Windows Kernel Information Disclosure Vulnerability","description":"Windows Kernel Information Disclosure Vulnerability","status":"published","published":"2021-06-08T22:46:25Z","modified":"2025-10-21T23:25:43.374Z","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:F/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-497"],"updated_at":"2026-11-02T14:33:05.665371Z"}],"euvd":[{"id":"EUVD-2021-18828","description":"Windows Kernel Information Disclosure Vulnerability","status":"published","published":"2021-06-08T22:46:25Z","modified":"2025-10-21T23:25:43Z","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:F/RL:O/RC:C","level":"medium"}],"exploited_since":"2021-11-03","updated_at":"2026-11-02T20:31:25.308373Z"}],"ghsa":[{"id":"GHSA-4grg-84cr-6c2h","title":"Windows Kernel Information Disclosure Vulnerability","description":"Windows Kernel Information Disclosure Vulnerability","status":"published","published":"2022-05-24T19:04:48Z","modified":"2025-10-22T00:32:14Z","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-200","CWE-497"],"updated_at":"2026-11-02T15:04:04.786232Z"}],"kev":[{"id":"CVE-2021-31955","title":"Microsoft Windows Kernel Information Disclosure Vulnerability","description":"Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.","cwes":["CWE-497"],"kev":{"date_added":"2021-11-03","due_date":"2021-11-17","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:17.050017Z"}],"nvd":[{"id":"CVE-2021-31955","description":"Windows Kernel Information Disclosure Vulnerability","status":"published","published":"2021-06-08T23:15:08.817Z","modified":"2026-06-17T03:52:33.813Z","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"},{"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"},{"version":"2.0","score":2.1,"vector":"AV:L/AC:L/Au:N/C:P/I:N/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-497"],"updated_at":"2026-11-02T14:06:54.439974Z"}]}}