CVE-2026-39399

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-113786 pypdf is a free and open-source pure-python PDF library. CWE-20
• CVE-2026-112081 A vulnerability was determined in hankcs HanLP up to 2.1.0-beta.64. CWE-20
• CVE-2026-111869 A vulnerability was identified in makeplane plane up to 1.4.2. CWE-20
• CVE-2026-100347 kin-openapi is a Go project for handling OpenAPI files. CWE-20
• CVE-2026-99999 In the Linux kernel, the following vulnerability has been resolved: ipv4: validate… CWE-20
• CVE-2026-107726 Hazelcast is a unified real-time data platform combining stream processing with a fast… CWE-20
• CVE-2026-105757 vLLM is an inference and serving engine for large language models. CWE-20
• CVE-2026-105756 vLLM is an inference and serving engine for large language models. CWE-20