{"id":"CVE-2026-72971","aliases":["EUVD-2026-56603","GHSA-mq4h-r45f-27gp"],"status":"published","title":"Windows Container Isolation FS Filter Driver (unionfs.sys) Tampering Vulnerability","description":"Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00364,"percentile":0.30489,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-59"],"published":"2026-08-11T17:05:40Z","modified":"2026-11-10T21:59:22Z","products":[{"vendor":"microsoft","product":"windows 11 version 26h1"},{"vendor":"microsoft","product":"windows_11_26h1"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72971","tags":["vendor-advisory","patch","Vendor Advisory","Patch"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72971"},{"url":"https://github.com/advisories/GHSA-mq4h-r45f-27gp"}],"sources":{"cve":[{"id":"CVE-2026-72971","title":"Windows Container Isolation FS Filter Driver (unionfs.sys) Tampering Vulnerability","description":"Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.","status":"published","published":"2026-08-11T17:05:40.177Z","modified":"2026-11-10T21:59:22.14Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-59"],"updated_at":"2026-11-10T22:48:53.557052Z"}],"euvd":[{"id":"EUVD-2026-56603","description":"Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.","status":"published","published":"2026-08-11T17:05:40Z","modified":"2026-11-10T21:59:22Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-10T23:24:17.329747Z"}],"ghsa":[{"id":"GHSA-mq4h-r45f-27gp","title":"Improper link resolution before file access ('link following') in Windows Container Isolation FS...","description":"Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.","status":"published","published":"2026-08-11T18:31:53Z","modified":"2026-08-11T18:32:00Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T15:10:20.59674Z"}],"nvd":[{"id":"CVE-2026-72971","description":"Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.","status":"published","published":"2026-08-11T17:19:15.22Z","modified":"2026-10-24T15:10:00.19Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T14:12:36.880938Z"}]}}