{"id":"CVE-2026-54982","title":"Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability","summary":"Integer underflow (wrap or wraparound) in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","cvssSource":"cna","cwe":["CWE-191"],"vendor":"Microsoft","product":"Windows 10 Version 1607","affected":["windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9339","windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.9020","windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7548","windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7548","windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875","windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875","windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525","windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26226","windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26226","windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23291","windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23291","windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9339","windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9339","windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9020","windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.9020","windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386","windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158","windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-07-15T03:59:07.223027Z"},"published":"2026-07-14","updated":"2026-09-17","sourceUpdated":"2026-09-17T22:28:55.868Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-54982","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54982","label":"Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability"}],"tags":["cve.org"],"epss":0.00535,"epssPercentile":0.44082,"ingestedAt":"2026-09-08T17:06:31.930Z","slug":"CVE-2026-54982","body":"## Overview\n\nInteger underflow (wrap or wraparound) in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.\n\n## Affected\n\n- `windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7548`\n- `windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7548`\n- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875`\n- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875`\n- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525`\n- `windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26226`\n- `windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26226`\n- `windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23291`\n- `windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23291`\n- `windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386`\n- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158`\n- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}