What is CVE-2026-39399?

CVE-2026-39399 is a critical-severity vulnerability in Nuget Nugetgallery, classified under Improper Input Validation. CVSS score: 9.6/10. Published 2026-04-14.

How severe is CVE-2026-39399?

Critical severity. CVSS v3 base score is 9.6 out of 10.

Path Traversal in Nuget Nugetgallery

CVE-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 met…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.005 (64.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H.

Affected products

Nuget Nugetgallery — versions < 0e80f87628349207cdcaf55358491f8a6f1ca276

Weakness classification (CWE)

References

https://github.com/NuGet/NuGetGallery/security/advisories/GHSA-9r3h-v4hx-rhfr (x_refsource_CONFIRM)
https://github.com/NuGet/NuGetGallery/commit/0e80f87628349207cdcaf55358491f8a6f1ca276 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-39399?: CVE-2026-39399 is a critical-severity vulnerability in Nuget Nugetgallery, classified under Improper Input Validation. CVSS score: 9.6/10. Published 2026-04-14.
How severe is CVE-2026-39399?: Critical severity. CVSS v3 base score is 9.6 out of 10.