{"id":"GHSA-jqwh-526h-c92j","summary":"Microsoft Kiota: Code Generation Literal Injection in Kiota PHP Generator","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`, `{$...}`) verbatim, which PHP evaluates at runtime instead of treating as literal text. This is the same class of code-generation literal-injection flaw previously fixed for the Ruby generator (`#` interpolation), recurring here as a missed variant for PHP's `$` 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.","aliases":["CVE-2026-59859"],"modified":"2026-08-17T15:00:08.071691724Z","published":"2026-07-24T15:46:46Z","database_specific":{"nvd_published_at":"2026-07-16T15:16:35Z","cwe_ids":["CWE-94"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"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"}],"affected":[{"package":{"name":"Microsoft.OpenApi.Kiota","ecosystem":"NuGet","purl":"pkg:nuget/Microsoft.OpenApi.Kiota"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.30.0"},{"fixed":"1.32.4"}]}],"versions":["1.30.0","1.31.0","1.31.1","1.32.0","1.32.1","1.32.2","1.32.3"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-jqwh-526h-c92j/GHSA-jqwh-526h-c92j.json"}},{"package":{"name":"Microsoft.OpenApi.Kiota.Builder","ecosystem":"NuGet","purl":"pkg:nuget/Microsoft.OpenApi.Kiota.Builder"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.30.0"},{"fixed":"1.32.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-jqwh-526h-c92j/GHSA-jqwh-526h-c92j.json"}},{"package":{"name":"Microsoft.OpenApi.Kiota","ecosystem":"NuGet","purl":"pkg:nuget/Microsoft.OpenApi.Kiota"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.29.1"}]}],"versions":["0.1.0-preview","0.1.1-preview","0.1.2-preview","0.1.3-preview","0.10.0-preview","0.11.0-preview","0.11.1-preview","0.2.0-preview","0.2.1-preview","0.3.0-preview","0.4.0-preview","0.5.0-preview","0.5.1-preview","0.6.0-preview","0.7.1-preview","0.8.3-preview","0.9.0-preview","1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.10.1","1.11.0","1.11.1","1.12.0","1.13.0","1.14.0","1.15.0","1.16.0","1.17.0","1.18.0","1.19.0","1.19.1","1.2.0","1.2.1","1.20.0","1.21.0","1.22.0","1.22.1","1.22.2","1.22.3","1.23.0","1.24.0","1.24.1","1.24.2","1.24.3","1.25.1","1.26.0","1.26.1","1.27.0","1.28.0","1.29.0","1.3.0","1.4.0","1.5.0","1.5.1","1.6.1","1.7.0","1.8.0","1.8.1","1.8.2","1.9.0","1.9.1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-jqwh-526h-c92j/GHSA-jqwh-526h-c92j.json"}},{"package":{"name":"Microsoft.OpenApi.Kiota.Builder","ecosystem":"NuGet","purl":"pkg:nuget/Microsoft.OpenApi.Kiota.Builder"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.29.1"}]}],"versions":["0.2.0-preview","0.3.0-preview","0.4.0-preview","0.5.0-preview","0.5.1-preview","0.6.0-preview","0.7.1-preview","1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.10.1","1.11.0","1.11.1","1.12.0","1.13.0","1.14.0","1.15.0","1.16.0","1.17.0","1.18.0","1.19.0","1.19.1","1.2.0","1.2.1","1.20.0","1.21.0","1.22.0","1.22.1","1.22.2","1.22.3","1.23.0","1.3.0","1.4.0","1.5.0","1.5.1","1.6.1","1.7.0","1.8.0","1.8.1","1.8.2","1.9.0","1.9.1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-jqwh-526h-c92j/GHSA-jqwh-526h-c92j.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","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"}]}