CVE-2026-45491

Description

Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.

CVSS Metrics

• v3.1•MEDIUM•Score: 6.2CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
• v3.1•MEDIUM•Score: 6.2CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
• v3.1•MEDIUM•Score: 6.8CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

EPSS Trends

Current EPSS score: 0.39%• Percentile: 31%

Techniques & Countermeasures

• CWE-59•Improper Link Resolution Before File Access ('Link Following')

  The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Systems

• microsoft•.net 10.0

  ≥ 10.0.0, < 10.0.9

• microsoft•.net 8.0

  ≥ 8.0, < 8.0.28 | ≥ 8.0.0, < 8.0.28

• microsoft•.net 9.0

  ≥ 9.0.0, < 9.0.17

• NuGet•Microsoft.NetCore.App.Runtime.linux-x64

  ≥ 8.0.0, < 8.0.28 | ≥ 9.0.0, < 9.0.17 | ≥ 10.0.0, < 10.0.9

• NuGet•Microsoft.NetCore.App.Runtime.osx-arm64

  ≥ 8.0.0, < 8.0.28 | ≥ 9.0.0, < 9.0.17 | ≥ 10.0.0, < 10.0.9

• NuGet•Microsoft.NetCore.App.Runtime.win-x64

  ≥ 8.0.0, < 8.0.28 | ≥ 9.0.0, < 9.0.17 | ≥ 10.0.0, < 10.0.9

References (5)

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45491
• https://github.com/dotnet/runtime/security/advisories/GHSA-7q4v-2mr6-5gpx
• https://nvd.nist.gov/vuln/detail/CVE-2026-45491
• https://github.com/dotnet/announcements/issues/404
• https://github.com/dotnet/runtime