Microsoft Kiota: Path/URL injection into generated Copilot plugin manifest via x-ai-* extensions

Date Jul 24, 2026
Type Vendor advisory
Signal Critical vendor advisory
Vendor / Product NuGet ยท Microsoft.OpenApi.Kiota
CVE CVE-2026-59864
Critical vendor advisory CVE-2026-59864

Summary

Microsoft Kiota: Path/URL injection into generated Copilot plugin manifest via x-ai-* extensions

Why it matters

GitHub has published a reviewed security advisory for Microsoft.OpenApi.Kiota. Prioritize it with other application dependency updates, especially because EPSS places it in the 67% percentile.

Operator check

Check whether Microsoft.OpenApi.Kiota is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 9.3. EPSS probability: 1.3%; percentile: 67%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.