{"id":"CVE-2026-26154","title":"Windows Server Update Service (WSUS) Tampering Vulnerability","summary":"Improper input validation in Windows Server Update Service allows an unauthorized attacker to perform tampering over a network.","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","cvssSource":"cna","cwe":["CWE-20"],"vendor":"Microsoft","product":"Windows Server 2012","affected":["windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26026","windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26026","windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23132","windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23132","windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9060","windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9060","windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8644","windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.8644","windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5020","windows_server_2022_23h2_edition_server_core_installation >= 10.0.25398.0 < 10.0.25398.2274","windows_server_2025 >= 10.0.26100.0 < 10.0.26100.32690","windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.32690"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-04-14T17:59:13.916318Z"},"published":"2026-04-14","updated":"2026-09-25","sourceUpdated":"2026-09-25T17:24:55.094Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-26154","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26154","label":"Windows Server Update Service (WSUS) Tampering Vulnerability"}],"tags":["cve.org"],"epss":0.01232,"epssPercentile":0.67705,"ingestedAt":"2026-09-25T18:14:20.461Z","slug":"CVE-2026-26154","body":"## Overview\n\nImproper input validation in Windows Server Update Service allows an unauthorized attacker to perform tampering over a network.\n\n## Affected\n\n- `windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26026`\n- `windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26026`\n- `windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23132`\n- `windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23132`\n- `windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9060`\n- `windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9060`\n- `windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8644`\n- `windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.8644`\n- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5020`\n- `windows_server_2022_23h2_edition_server_core_installation >= 10.0.25398.0 < 10.0.25398.2274`\n- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.32690`\n- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.32690`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}