{"id":"CVE-2026-40420","aliases":["EUVD-2026-29677","GHSA-q3w4-cjqg-q4x3"],"status":"published","title":"Microsoft Office Click-To-Run Elevation of Privilege Vulnerability","description":"Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00212,"percentile":0.11546,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-284"],"published":"2026-05-12T16:59:29Z","modified":"2026-10-26T18:10:00Z","products":[{"vendor":"microsoft","product":"365_apps"},{"vendor":"microsoft","product":"microsoft 365 apps for enterprise"},{"vendor":"microsoft","product":"microsoft office 2019"},{"vendor":"microsoft","product":"microsoft office ltsc 2021"},{"vendor":"microsoft","product":"microsoft office ltsc 2024"},{"vendor":"microsoft","product":"office"},{"vendor":"microsoft","product":"office_long_term_servicing_channel"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40420","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40420"},{"url":"https://github.com/advisories/GHSA-q3w4-cjqg-q4x3"}],"sources":{"cve":[{"id":"CVE-2026-40420","title":"Microsoft Office Click-To-Run Elevation of Privilege Vulnerability","description":"Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-05-12T16:59:29.493Z","modified":"2026-08-10T15:13:37.172Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T13:43:11.445168Z"}],"euvd":[{"id":"EUVD-2026-29677","description":"Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-05-12T16:59:29Z","modified":"2026-08-10T15:13:37Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:02:01.941928Z"}],"ghsa":[{"id":"GHSA-q3w4-cjqg-q4x3","title":"Improper access control in Microsoft Office Click-To-Run allows an authorized attacker to elevate...","description":"Improper access control in Microsoft Office Click-To-Run allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-05-12T18:30:45Z","modified":"2026-05-12T18:30:54Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T15:08:05.647564Z"}],"nvd":[{"id":"CVE-2026-40420","description":"Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-05-12T18:17:20.19Z","modified":"2026-10-26T18:10:00.173Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T14:12:18.613259Z"}]}}