CVE-2026-59866
Microsoft Kiota: Arbitrary file write + code-injection via x-ms-kiota-info clientClassName and clientNamespaceName
Impact
Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.5, Kiota emitted x-ms-kiota-info clientClassName and clientNamespaceName values without identifier or path sanitization as both generated client class or namespace names and generated output path components when `kiota generate` ran without -c/--class-name, allowing an attacker-controlled or compromised OpenAPI description to write generated source outside the -o output directory and inject arbitrary text into generated class or namespace declarations. This issue is fixed in version 1.29.1 and 1.32.5 by GenerationConfiguration.SanitizeClientClassName and SanitizeClientNamespaceName.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| nuget | Microsoft.OpenApi.Kiota | >= 1.30.0, < 1.32.5 | 1.32.5 |
| nuget | Microsoft.OpenApi.Kiota.Builder | >= 1.30.0, < 1.32.5 | 1.32.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-4vv7-jj25-4gh6
- https://github.com/microsoft/kiota/security/advisories/GHSA-4vv7-jj25-4gh6
- https://nvd.nist.gov/vuln/detail/CVE-2026-59866
- https://github.com/microsoft/kiota/pull/7884
- https://github.com/microsoft/kiota/commit/dc812dbbf88ef7edf53a890d36b2f9d1460e947d
- https://github.com/microsoft/kiota/releases/tag/v1.32.5