Vulnerability-Lookup

GHSA-RG4H-FPCP-2QM8

Vulnerability from github – Published: 2026-07-24 16:10 – Updated: 2026-07-24 16:10

Summary

Microsoft Kiota: Generation-time SSRF + remote/local file inclusion via unrestricted $ref

Details

Summary

Microsoft Kiota resolved OpenAPI $refs by fetching remote http(s) URLs and reading local files (including absolute / out-of-tree paths), inlining the referenced schema into the generated client. Running kiota generate on a spec whose $ref pointed at an attacker/internal URL or an arbitrary local file yielded SSRF, remote file inclusion, and local file inclusion. Verified on 1.32.3 / 1.32.4.

Details

$ref: http://attacker/internal-evil.json#/... → build host fetches the URL (SSRF) and inlines the remote schema (RFI); confirmed property REMOTE_KIOTA_PROP in the generated client.
$ref: /abs/path.json#/... or ../../secret.json#/... → Kiota reads the out-of-tree local file and inlines its schema (LFI); confirmed Leaked schema in the generated client. Resolution is transitive across nesting levels.

Kiota escapes its output sinks (comments/strings/identifiers), so attacker-controlled remote/local content cannot break out into code — no RCE. The chain stops at SSRF + RFI + LFI.

Impact

Build-time SSRF (CWE-918) from the developer or CI host, disclosure of arbitrary local files (CWE-22), and inclusion of untrusted remote content (CWE-829), from running the generator on an attacker-controlled or attacker-influenced OpenAPI description. No code execution. Notable because Kiota is otherwise the hardened generator (it resists the code-injection class).

The relevant threat is not "change the generated output" (an attacker who fully controls the description can already do that) but the side effects on the build host: outbound requests from inside the CI network (cloud metadata, internal-only services) and reads of local files the attacker never possessed, whose contents are then inlined into the generated — and typically committed/published — client. It also bypasses controls that review the description document but not externally-referenced content.

Patches

Fixed in 1.32.5 (https://github.com/microsoft/kiota/pull/7888). External reference resolution is now default-deny: a new AllowedExternalOriginsStreamLoader refuses to load any external $ref — remote http(s) URLs and local file paths alike — unless its origin/path is explicitly allow-listed. A new --allowed-external-origins parameter (added to the commands that load OpenAPI descriptions) opts specific origins back in, accepting *, full URIs, URI patterns, full paths, relative paths, or path patterns (wildcards supported). With no allow-list entries, external references are not loaded at all.

Remediation

Upgrade to Kiota 1.32.5 or later. External references now require explicit opt-in via --allowed-external-origins; add only trusted origins/paths.

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.32.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota.Builder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.32.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59867"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-829",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T16:10:17Z",
    "nvd_published_at": "2026-07-16T16:19:15Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nMicrosoft Kiota resolved OpenAPI `$ref`s by fetching remote `http(s)` URLs and reading local files\n(including absolute / out-of-tree paths), inlining the referenced schema into the generated client.\nRunning `kiota generate` on a spec whose `$ref` pointed at an attacker/internal URL or an arbitrary\nlocal file yielded SSRF, remote file inclusion, and local file inclusion. Verified on **1.32.3 / 1.32.4**.\n\n### Details\n\n- `$ref: http://attacker/internal-evil.json#/...` \u2192 build host fetches the URL (SSRF) and inlines the\n  remote schema (RFI); confirmed property `REMOTE_KIOTA_PROP` in the generated client.\n- `$ref: /abs/path.json#/...` or `../../secret.json#/...` \u2192 Kiota reads the out-of-tree local file and\n  inlines its schema (LFI); confirmed `Leaked` schema in the generated client. Resolution is transitive\n  across nesting levels.\n\nKiota **escapes** its output sinks (comments/strings/identifiers), so attacker-controlled remote/local\ncontent cannot break out into code \u2014 no RCE. The chain stops at SSRF + RFI + LFI.\n\n### Impact\n\nBuild-time SSRF (CWE-918) from the developer or CI host, disclosure of arbitrary local files (CWE-22), and\ninclusion of untrusted remote content (CWE-829), from running the generator on an attacker-controlled or\nattacker-influenced OpenAPI description. No code execution. Notable because Kiota is otherwise the hardened\ngenerator (it resists the code-injection class).\n\nThe relevant threat is not \"change the generated output\" (an attacker who fully controls the description can\nalready do that) but the **side effects on the build host**: outbound requests from inside the CI network\n(cloud metadata, internal-only services) and reads of local files the attacker never possessed, whose contents\nare then inlined into the generated \u2014 and typically committed/published \u2014 client. It also bypasses controls\nthat review the description document but not externally-referenced content.\n\n### Patches\n\nFixed in **1.32.5** (https://github.com/microsoft/kiota/pull/7888). External reference resolution is now\n**default-deny**: a new `AllowedExternalOriginsStreamLoader` refuses to load any external `$ref` \u2014 remote\n`http(s)` URLs and local file paths alike \u2014 unless its origin/path is explicitly allow-listed. A new\n`--allowed-external-origins` parameter (added to the commands that load OpenAPI descriptions) opts specific\norigins back in, accepting `*`, full URIs, URI patterns, full paths, relative paths, or path patterns\n(wildcards supported). With no allow-list entries, external references are not loaded at all.\n\n### Remediation\n\nUpgrade to Kiota **1.32.5** or later. External references now require explicit opt-in via\n`--allowed-external-origins`; add only trusted origins/paths.",
  "id": "GHSA-rg4h-fpcp-2qm8",
  "modified": "2026-07-24T16:10:17Z",
  "published": "2026-07-24T16:10:17Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/security/advisories/GHSA-rg4h-fpcp-2qm8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59867"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/pull/7888"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/commit/cccd798027f0a20db796b3df6c64f9897a39d7b1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/microsoft/kiota"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/releases/tag/v1.32.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Microsoft Kiota: Generation-time SSRF + remote/local file inclusion via unrestricted $ref"
}

CVE-2026-59867 (GCVE-0-2026-59867)

Vulnerability from cvelistv5 – Published: 2026-07-16 14:48 – Updated: 2026-07-16 15:37

Title

Kiota: Generation-time SSRF + remote/local file inclusion via unrestricted $ref

Summary

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.32.5, Kiota resolved OpenAPI $ref values by fetching remote http(s) URLs and reading local absolute or out-of-tree file paths, allowing `kiota generate` on an attacker-controlled or attacker-influenced description to perform build-time SSRF, remote file inclusion, and local file inclusion by inlining external schemas such as REMOTE_KIOTA_PROP or Leaked into generated clients. This issue is fixed in version 1.32.5 by AllowedExternalOriginsStreamLoader and the --allowed-external-origins option.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-829 - Inclusion of Functionality from Untrusted Control Sphere
CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/microsoft/kiota/security/advis…	x_refsource_CONFIRM
https://github.com/microsoft/kiota/pull/7888	x_refsource_MISC
https://github.com/microsoft/kiota/commit/cccd798…	x_refsource_MISC
https://github.com/microsoft/kiota/releases/tag/v1.32.5	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
microsoft	kiota	Affected: < 1.32.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-59867",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-16T15:35:45.668795Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-16T15:37:02.124Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "kiota",
          "vendor": "microsoft",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.32.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.32.5, Kiota resolved OpenAPI $ref values by fetching remote http(s) URLs and reading local absolute or out-of-tree file paths, allowing `kiota generate` on an attacker-controlled or attacker-influenced description to perform build-time SSRF, remote file inclusion, and local file inclusion by inlining external schemas such as REMOTE_KIOTA_PROP or Leaked into generated clients. This issue is fixed in version 1.32.5 by AllowedExternalOriginsStreamLoader and the --allowed-external-origins option."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-829",
              "description": "CWE-829: Inclusion of Functionality from Untrusted Control Sphere",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-16T14:48:11.958Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/microsoft/kiota/security/advisories/GHSA-rg4h-fpcp-2qm8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/microsoft/kiota/security/advisories/GHSA-rg4h-fpcp-2qm8"
        },
        {
          "name": "https://github.com/microsoft/kiota/pull/7888",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/microsoft/kiota/pull/7888"
        },
        {
          "name": "https://github.com/microsoft/kiota/commit/cccd798027f0a20db796b3df6c64f9897a39d7b1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/microsoft/kiota/commit/cccd798027f0a20db796b3df6c64f9897a39d7b1"
        },
        {
          "name": "https://github.com/microsoft/kiota/releases/tag/v1.32.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/microsoft/kiota/releases/tag/v1.32.5"
        }
      ],
      "source": {
        "advisory": "GHSA-rg4h-fpcp-2qm8",
        "discovery": "UNKNOWN"
      },
      "title": "Kiota: Generation-time SSRF + remote/local file inclusion via unrestricted $ref"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-59867",
    "datePublished": "2026-07-16T14:48:11.958Z",
    "dateReserved": "2026-07-07T15:41:53.607Z",
    "dateUpdated": "2026-07-16T15:37:02.124Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-RG4H-FPCP-2QM8

Summary

Details

Impact

Patches

Remediation

CVE-2026-59867 (GCVE-0-2026-59867)

Tags

Sightings

Nomenclature