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CVE-2026-39399

NuGet Gallery is a package repository that powers nuget.org.

Published Apr 14, 2026 · updated Jul 24, 2026

NuGet Gallery is a package repository that powers nuget.org. A security vulnerability exists in the NuGetGallery backend job’s handling of .nuspec files within NuGet packages. An attacker can supply a crafted nuspec file with malicious metadata, leading to cross package metadata injection that may result in remote code execution (RCE) and/or arbitrary blob writes due to insufficient input validation. The issue is exploitable via URI fragment injection using unsanitized package identifiers, allowing an attacker to control the resolved blob path. This enables writes to arbitrary blobs within the storage container, not limited to .nupkg files, resulting in potential tampering of existing content. This issue has been patched in commit 0e80f87628349207cdcaf55358491f8a6f1ca276.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 14, 2026 · NIST NVD

    Detected

    NuGet Gallery is a package repository that powers nuget.org. A security vulnerability exists in the NuGetGallery backend job’s handling of .nuspec files within NuGet packages. An attacker can supply a crafted nuspec file with malicious metadata, leading to cross package metadata injection that may result in remote code execution (RCE) and/or arbitrary blob writes due to insufficient input validati

  2. Jul 24, 2026 · NIST NVD

    Updated

    NuGet Gallery is a package repository that powers nuget.org. A security vulnerability exists in the NuGetGallery backend job’s handling of .nuspec files within NuGet packages. An attacker can supply a crafted nuspec file with malicious metadata, leading to cross package metadata injection that may result in remote code execution (RCE) and/or arbitrary blob writes due to insufficient input validati

Sources

  • CVE.orgVulnerability recordCVE-2026-39399

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-39399

    NuGet Gallery is a package repository that powers nuget.org. A security vulnerability exists in the NuGetGallery backend job’s handling of .nuspec files within NuGet packages. An attacker can supply a crafted nuspec file with malicious metadata, leading to cross package metadata

    nvd.nist.gov

References