CVE-2026-59864: Microsoft Kiota Path/URL Injection Into Generated Copilot Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4jwf-m4wg-8p66",
  "modified" : "2026-08-17T14:54:42Z",
  "published" : "2026-07-24T15:58:31Z",
  "aliases" : [ "CVE-2026-59864" ],
  "summary" : "Microsoft Kiota: Path/URL injection into generated Copilot plugin manifest via x-ai-* extensions",
  "details" : "### Summary\n\n`kiota plugin add` / `kiota plugin generate` (with `-t APIPlugin`) emits an attacker-controlled `static_template.file` path from the AI-plugin extensions (`x-ai-adaptive-card`, `x-ai-capabilities`) **verbatim**, with no path validation, into the generated Microsoft 365 Copilot / Teams plugin manifest (`<name>-apiplugin.json`). An attacker-controlled or compromised OpenAPI description can therefore embed a `../` / absolute path into the manifest's `response_semantics.static_template.file`, yielding a **path traversal (CWE-22)** / out-of-package file inclusion (CWE-829) that is resolved by the AI host when the generated plugin is deployed.\n\nConfirmed on Kiota **1.32.4** (`KIOTA_CONFIG_PREVIEW=true`, the self-contained `linux-x64` release binary).\n\n### Details\n\nBoth extension paths write the `static_template.file` reference straight into the manifest without sanitization — `PluginsGenerationService.GetResponseSemanticsFromAdaptiveCardExtension` mints `static_template = {\"file\": <File>}`, and the `x-ai-capabilities` path copies the `static_template` object through:\n\n```\n# spec                                                  -> generated manifest (functions[].capabilities.response_semantics)\nx-ai-adaptive-card: {title: T, data_path: $.x,\n   file: \"../../../../../../etc/passwd\"}                -> static_template.file = \"../../../../../../etc/passwd\"   (CWE-22)\nx-ai-capabilities.response_semantics.static_template:\n   {file: \"../../../../../../etc/passwd\"}               -> static_template.file = \"../../../../../../etc/passwd\"   (CWE-22)\n```\n\n(`x-ai-adaptive-card.file` only reaches the manifest when `title` is set, so `GetResponseSemanticsFromAdaptiveCardExtension` fires; otherwise kiota writes its own template card instead.)\n\n### Impact\n\n**This is not local code execution on the build host.** The injected path is written into the generated plugin manifest and realized **downstream**, when the plugin is packaged and sideloaded / deployed to an AI host (Microsoft 365 Copilot / Teams) that resolves `static_template.file` relative to the plugin package (out-of-package file reference via `../`). Kiota is the propagation point: it fails to reject `../` and absolute paths in this provider-supplied field before writing it into the manifest.\n\n### Patches\n\nFixed in **1.29.1 and 1.32.5** (https://github.com/microsoft/kiota/pull/7892). `static_template.file` from both `x-ai-adaptive-card` and `x-ai-capabilities` is validated as a relative path confined to the plugin output package: absolute URIs, rooted/UNC paths, Windows drive paths, and `..` traversal segments are rejected, and unsafe references are dropped with a warning. Regression tests cover `..`, absolute paths, and URI values.\n\n### Remediation\n\nUpgrade to Kiota **1.29.1, 1.32.5** or later and regenerate affected plugins.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.OpenApi.Kiota"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.30.0"
      }, {
        "fixed" : "1.32.5"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.OpenApi.Kiota.Builder"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.30.0"
      }, {
        "fixed" : "1.32.5"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.OpenApi.Kiota"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.29.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.OpenApi.Kiota.Builder"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.29.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/kiota/security/advisories/GHSA-4jwf-m4wg-8p66"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-59864"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/kiota/pull/7892"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/kiota/commit/9a185994a4e549b7bba3cc2beffb9736aa902e79"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/microsoft/kiota"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/kiota/releases/tag/v1.32.5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-829" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-24T15:58:31Z",
    "nvd_published_at" : "2026-07-16T16:19:15Z"
  }
}