{"id":"CVE-2026-56648","title":"Time-of-check time-of-use (toctou) race condition in Windows Network File System allows an authorized attacker to elevate privileges over a network.","summary":"Time-of-check time-of-use (toctou) race condition in Windows Network File System allows an authorized attacker to elevate privileges over a network.","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-367","CWE-416"],"vendor":"microsoft","product":"windows_10_1607","affected":["windows_10_1607 < 10.0.14393.9339","windows_10_1809 < 10.0.17763.9020","windows_10_21h2 < 10.0.19044.7548","windows_10_22h2 < 10.0.19045.7548","windows_11_24h2 < 10.0.26100.8875","windows_11_25h2 < 10.0.26200.8875","windows_11_26h1 < 10.0.28000.2269","windows_server_2012","windows_server_2012 = r2","windows_server_2016 < 10.0.14393.9339","windows_server_2019 < 10.0.17763.9020","windows_server_2022 < 10.0.20348.5386","windows_server_2025 < 10.0.26100.33158"],"patched":["windows_10_1607 10.0.14393.9339","windows_10_1809 10.0.17763.9020","windows_10_21h2 10.0.19044.7548","windows_10_22h2 10.0.19045.7548","windows_11_24h2 10.0.26100.8875","windows_11_25h2 10.0.26200.8875","windows_11_26h1 10.0.28000.2269","windows_server_2016 10.0.14393.9339","windows_server_2019 10.0.17763.9020","windows_server_2022 10.0.20348.5386","windows_server_2025 10.0.26100.33158"],"published":"2026-07-14","updated":"2026-07-17","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-56648","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56648","label":"secure@microsoft.com"}],"tags":["nvd","cve.org"],"epss":0.00509,"epssPercentile":0.42425,"ingestedAt":"2026-07-18T13:23:33.396Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-07-14T00:00:00+00:00"},"slug":"CVE-2026-56648","body":"## Overview\n\nTime-of-check time-of-use (toctou) race condition in Windows Network File System allows an authorized attacker to elevate privileges over a network.\n\n## Affected\n\n- `windows_10_1607 < 10.0.14393.9339`\n- `windows_10_1809 < 10.0.17763.9020`\n- `windows_10_21h2 < 10.0.19044.7548`\n- `windows_10_22h2 < 10.0.19045.7548`\n- `windows_11_24h2 < 10.0.26100.8875`\n- `windows_11_25h2 < 10.0.26200.8875`\n- `windows_11_26h1 < 10.0.28000.2269`\n- `windows_server_2012`\n- `windows_server_2012 = r2`\n- `windows_server_2016 < 10.0.14393.9339`\n- `windows_server_2019 < 10.0.17763.9020`\n- `windows_server_2022 < 10.0.20348.5386`\n- `windows_server_2025 < 10.0.26100.33158`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `windows_10_1607 10.0.14393.9339`\n- `windows_10_1809 10.0.17763.9020`\n- `windows_10_21h2 10.0.19044.7548`\n- `windows_10_22h2 10.0.19045.7548`\n- `windows_11_24h2 10.0.26100.8875`\n- `windows_11_25h2 10.0.26200.8875`\n- `windows_11_26h1 10.0.28000.2269`\n- `windows_server_2016 10.0.14393.9339`\n- `windows_server_2019 10.0.17763.9020`\n- `windows_server_2022 10.0.20348.5386`\n- `windows_server_2025 10.0.26100.33158`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}