{
  "affected": [
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.30.0"
            },
            {
              "fixed": "1.32.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota.Builder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.30.0"
            },
            {
              "fixed": "1.32.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.29.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi.Kiota.Builder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.29.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59859"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T15:46:46Z",
    "nvd_published_at": "2026-07-16T15:16:35Z",
    "severity": "HIGH"
  },
  "details": "# Impact\n\nThe Kiota PHP code generator is vulnerable to a code generation literal injection attack. The generator embeds string values from OpenAPI fields (e.g. `description`, default values, and property names) directly into PHP double-quoted string literals without properly escaping the `$` character. Since PHP evaluates string interpolation expressions like `\"${expr}\"`, `\"$var\"`, and `\"{$obj-\u003eprop}\"` within double-quoted strings at runtime, an attacker who controls an OpenAPI specification file can inject arbitrary PHP code into generated model and request-builder classes.\n\n# Who is impacted\n\nDevelopers using Kiota to generate PHP API clients from external or untrusted OpenAPI specifications\n\nTeams with CI/CD pipelines configured to automatically regenerate client code from remote specs\n\nApplications that deploy generated PHP code to production servers\n\n# Vulnerability details\n\nAffected component: `StringExtensions.cs`\n\nRoot cause: The shared `SanitizeDoubleQuote()` function in `Writers/StringExtensions.cs` does not escape the `$` character. As a result, any schema-derived string emitted as a PHP double-quoted literal preserves `$`-prefixed interpolation constructs (`${...}`, `$var`, `{$...}`) verbatim, which PHP evaluates at runtime instead of treating as literal text. This is the same class of code-generation literal-injection flaw previously fixed for the Ruby generator (`#` interpolation), recurring here as a missed variant for PHP\u0027s `$` interpolation in the sibling sanitizer helper.\n\n# Attack vectors\n\nOpenAPI `description` and default fields in schema properties\n\nProperty wire-name keys embedded in deserializer/serializer methods\n\nAny schema-derived string embedded in PHP double-quoted literals\n\nSeverity: Critical when generated code reaches production; High for CI/CD environments with access to production secrets; Medium for public third-party specs; Low for developer-controlled specs.\n\n# Patches\n\n[#7863](https://github.com/microsoft/kiota/pull/7863)\n\n# Workarounds\n\nIf you cannot upgrade immediately:\n\n1. Audit and sanitize OpenAPI specifications: Review all OpenAPI specification files for any descriptions, default values, or property names containing the `$` character. Remove or replace any suspicious strings before code generation.\n2. Code review of generated files: Implement mandatory code review of all generated PHP files before merging into any branch. Look for double-quoted strings containing `${`, `$var`, or `{$` patterns.\n3. Restrict specification sources: Only consume OpenAPI specifications from trusted internal sources. Avoid automatic code generation from external or third-party APIs until this patch is applied.\n4. Isolate generated code from production: Do not deploy generated PHP models to production environments unless the specification source has been verified and reviewed.\n5. Manual escaping (temporary): If regeneration is not possible, manually inspect and edit generated files to escape any `$` characters in double-quoted string literals (replace `$` with `\\$`).\n\n# Remediation\n\nUpgrade Kiota to 1.29.1, 1.32.4, or later.\n\nRegenerate/refresh existing generated clients as a precaution:\n\nRefreshing generated clients ensures previously generated vulnerable code is replaced with hardened output.",
  "id": "GHSA-jqwh-526h-c92j",
  "modified": "2026-08-17T14:53:45Z",
  "published": "2026-07-24T15:46:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/security/advisories/GHSA-jqwh-526h-c92j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59859"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/pull/7863"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/commit/5e2a211ac4261988fbdc72c3b268596ea8837b87"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/microsoft/kiota"
    },
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/kiota/releases/tag/v1.32.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Microsoft Kiota: Code Generation Literal Injection in Kiota PHP Generator"
}