{"id":"CVE-2026-45491","title":".NET Tampering Vulnerability","summary":"Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.","severity":"medium","cvss":6.2,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","cvssSource":"cna","cwe":["CWE-59"],"vendor":"Microsoft","product":".NET 10.0","affected":[".net_10.0 >= 10.0.0 < 10.0.9",".net_8.0 >= 8.0 < 8.0.28",".net_8.0 >= 8.0.0 < 8.0.28",".net_9.0 >= 9.0.0 < 9.0.17"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-06-10T12:17:16.966103Z"},"published":"2026-06-09","updated":"2026-09-24","sourceUpdated":"2026-09-24T13:43:46.222Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-45491","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45491","label":".NET Tampering Vulnerability"},{"url":"https://github.com/dotnet/runtime/security/advisories/GHSA-7q4v-2mr6-5gpx"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45491"},{"url":"https://github.com/dotnet/announcements/issues/404"},{"url":"https://github.com/advisories/GHSA-7q4v-2mr6-5gpx"}],"tags":["cve.org","ghsa","nuget"],"epss":0.00388,"epssPercentile":0.32745,"aliases":["GHSA-7q4v-2mr6-5gpx"],"ecosystem":"nuget","patched":["Microsoft.NETCore.App.Runtime.linux-x64 8.0.28","Microsoft.NETCore.App.Runtime.linux-x64 9.0.17","Microsoft.NETCore.App.Runtime.linux-x64 10.0.9","Microsoft.NETCore.App.Runtime.win-x64 8.0.28","Microsoft.NETCore.App.Runtime.win-x64 9.0.17","Microsoft.NETCore.App.Runtime.win-x64 10.0.9","Microsoft.NETCore.App.Runtime.osx-arm64 8.0.28","Microsoft.NETCore.App.Runtime.osx-arm64 9.0.17","Microsoft.NETCore.App.Runtime.osx-arm64 10.0.9"],"scores":{"cna":6.2,"ghsa":6.8},"ingestedAt":"2026-07-07T15:41:58.347Z","slug":"CVE-2026-45491","body":"## Overview\n\nImproper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.\n\n## Affected\n\n- `.net_10.0 >= 10.0.0 < 10.0.9`\n- `.net_8.0 >= 8.0 < 8.0.28`\n- `.net_8.0 >= 8.0.0 < 8.0.28`\n- `.net_9.0 >= 9.0.0 < 9.0.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-45491)\n\nAffected packages:\n\n- `Microsoft.NETCore.App.Runtime.linux-x64 >= 8.0.0, <= 8.0.27`\n- `Microsoft.NETCore.App.Runtime.linux-x64 >= 9.0.0, <= 9.0.16`\n- `Microsoft.NETCore.App.Runtime.linux-x64 >= 10.0.0, <= 10.0.8`\n- `Microsoft.NETCore.App.Runtime.win-x64 >= 8.0.0, <= 8.0.27`\n- `Microsoft.NETCore.App.Runtime.win-x64 >= 9.0.0, <= 9.0.16`\n- `Microsoft.NETCore.App.Runtime.win-x64 >= 10.0.0, <= 10.0.8`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 8.0.0, <= 8.0.27`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 9.0.0, <= 9.0.16`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 10.0.0, <= 10.0.8`\n\nPatched in:\n\n- `Microsoft.NETCore.App.Runtime.linux-x64 8.0.28`\n- `Microsoft.NETCore.App.Runtime.linux-x64 9.0.17`\n- `Microsoft.NETCore.App.Runtime.linux-x64 10.0.9`\n- `Microsoft.NETCore.App.Runtime.win-x64 8.0.28`\n- `Microsoft.NETCore.App.Runtime.win-x64 9.0.17`\n- `Microsoft.NETCore.App.Runtime.win-x64 10.0.9`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 8.0.28`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 9.0.17`\n- `Microsoft.NETCore.App.Runtime.osx-arm64 10.0.9`\n\nSource: https://github.com/advisories/GHSA-7q4v-2mr6-5gpx","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":34.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":210166,"id":"CVE-2026-45491","ts":1790261142356,"field":"cvss","old":"6.8","new":"6.2"}]}