GHSA-xg2h-5xr2-29jw is a high-severity (CVSS 7.5) Code Injection vulnerability in Microsoft.OpenAPI.Kiota. O3 Security confirms whether GHSA-xg2h-5xr2-29jw is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Microsoft Kiota: Code Generation Literal Injection in Kiota Ruby Generator
Real-World Exposure
Microsoft.OpenAPI.Kiota.NETMicrosoft.OpenAPI.Kiota.Builder.NETMicrosoft.OpenApi.Kiota.NETMicrosoft.OpenApi.Kiota.BuilderReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Code Generation Literal Injection in Kiota Ruby Generator Leads to Arbitrary Code Execution
Impact
The Kiota Ruby code generator is vulnerable to a code generation literal injection attack. The generator embeds string values from OpenAPI default fields and property names directly into Ruby double-quoted string literals without properly escaping the # character. Since Ruby evaluates string interpolation expressions like #{expr}, #$var, and #@var within double-quoted strings at runtime, an attacker who controls an OpenAPI specification file can inject arbitrary Ruby code into generated model classes.
Who is impacted
Developers using Kiota to generate Ruby API clients from external or untrusted OpenAPI specifications Teams with CI/CD pipelines configured to automatically regenerate client code from remote specs Applications that deploy generated Ruby code to production servers
Vulnerability details
Affected component: CodeMethodWriter.cs Root cause: The shared SanitizeForQuotedLiteral() function in Writers/StringExtensions.cs does not escape the # character
Attack vectors
OpenAPI default fields in schema properties Property wire-name hash keys in deserializer/serializer methods Any schema-derived string embedded in Ruby double-quoted literals Severity: Critical when generated code reaches production; High for CI/CD environments with access to production secrets; Medium for public third-party specs; Low for developer-controlled specs.
Patches
https://github.com/microsoft/kiota/pull/7746
Workarounds
If you cannot upgrade immediately:
- Audit and sanitize OpenAPI specifications: Review all OpenAPI specification files for any default values or property names containing the # character. Remove or replace any suspicious strings before code generation.
- Code review of generated files: Implement mandatory code review of all generated Ruby files before merging into any branch. Look for double-quoted strings containing #{, #$, or #@ patterns.
- 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.
- Isolate generated code from production: Do not deploy generated Ruby models to production environments unless the specification source has been verified and reviewed.
- Manual escaping (temporary): If regeneration is not possible, manually inspect and edit generated files to escape any # characters in string literals (replace # with # in double-quoted strings).
Remediation
Upgrade Kiota to 1.29.1, 1.32.0, or later. Regenerate/refresh existing generated clients as a precaution:
kiota update
Refreshing generated clients ensures previously generated vulnerable code is replaced with hardened output.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.OpenAPI.Kiota | ≥ 1.30.0&&< 1.32.0 | 1.32.0 |
| .NETNuGet | Microsoft.OpenAPI.Kiota.Builder | ≥ 1.30.0&&< 1.32.0 | 1.32.0 |
| .NETNuGet | Microsoft.OpenApi.Kiota | all versions | 1.29.1 |
| .NETNuGet | Microsoft.OpenApi.Kiota.Builder | all versions | 1.29.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.OpenAPI.Kiota. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Microsoft.OpenAPI.Kiota to 1.32.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xg2h-5xr2-29jw is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xg2h-5xr2-29jw is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xg2h-5xr2-29jw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xg2h-5xr2-29jw in your dependencies?
O3 detects GHSA-xg2h-5xr2-29jw across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.