Hi @peter.shrosbree, Thank you for your detailed analysis of this issue. We were able to discover a version mismatch error in our NuGet V3 Package Metadata API. Once we retrieved vulnerabilities for a package name, we built the vulnerability array for each version by only checking for a version, not package name. So vulnerabilities that had multiple package names associated could show for multiple packages. This is only an issue with the NuGet API, as internal ProGet mechanisms check differently. Turns out this has been an issue for quite a while now, but it only became noticeable once we launched the NuGet Vulnerability API implementation in 2026.11. We will have this fixed, PG-3410, in tomorrows release of ProGet 2026.13. There is also an issue, PG-3401, that fixes an issue in the NuGet Vulnerability API when a single version is affected. As for the security.inedo.com page for PG-2129406, the version range is actually correct. The version range of ≥ 4.0.0 & < 4.5.1 is the same as [4.0.0,4.5.1) which means versions greater than or equal to 4.0.0 and less than 4.5.1. That is why the package in the ProGet UI did not display a vulnerability for 8.0.0 - 9.0.21. Please let us know if you need better clarification on any of this. Thanks, Rich