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HIGH severity

GHSA-7f3j-j7jj-r3vr

HIGH

GHSA-7f3j-j7jj-r3vr is a high-severity (CVSS 7.5) Code Injection vulnerability in Microsoft.OpenAPI.Kiota. O3 Security confirms whether GHSA-7f3j-j7jj-r3vr 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 Python Generator

Also known asCVE-2026-59862
Published
Jul 24, 2026
Updated
Aug 17, 2026
Affected
4 pkgs
Patched
4 / 4
Exploits
None indexed
Exploitation data as of Aug 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

4 pkgs affected
.NETMicrosoft.OpenAPI.Kiota.NETMicrosoft.OpenAPI.Kiota.Builder.NETMicrosoft.OpenApi.Kiota.NETMicrosoft.OpenApi.Kiota.Builder

Real-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 Python Generator Leads to Arbitrary Code Execution at Import Time.

The Kiota Python code generator is vulnerable to a code generation literal injection issue when processing malicious or untrusted OpenAPI specifications. Specifically, attacker-controlled enum value descriptions from x-ms-enum.values[].description can flow into generated Python files without newline sanitization, allowing injected content to escape a comment context and execute at module scope when the generated module is imported.

This issue requires user interaction in the form of generating a client from a malicious specification and importing the generated code, which is a common development and CI workflow.

Impact

A malicious OpenAPI specification can cause arbitrary Python code to be emitted into generated model files. The payload executes when the affected module is imported.

Potential impact includes

Credential theft from developer or CI environments Exfiltration of environment variables and secrets Source code disclosure Persistence via regenerated backdoored client output Who is impacted Developers generating Python SDKs from external or untrusted OpenAPI specs Teams with CI/CD automation that regenerates clients from remote specification URLs Any environment importing generated Python modules before manual review Vulnerability details Two gaps combine to enable exploitation:

Enum description cleanup gap

In KiotaBuilder.SetEnumOptions, enum option descriptions are assigned to Documentation.DescriptionTemplate without CleanupDescription on this path, allowing control characters such as newlines to propagate.

Python description sanitization gap

PythonConventionService.RemoveInvalidDescriptionCharacters escapes backslashes and triple quotes but did not remove carriage return/newline characters, unlike some other language convention services.

Exploit path

Malicious newline in x-ms-enum description is emitted through enum writing path. Generated inline comment output is split by newline. Subsequent attacker-controlled line lands at module scope in generated .py file. Importing the module executes the injected code.

Attack vectors

OpenAPI specifications hosted at attacker-controlled URLs Supply-chain scenarios where third-party specs are consumed automatically CI pipelines that generate and then import or test generated Python clients

Patches

https://github.com/microsoft/kiota/pull/7735

Workarounds

If you cannot upgrade immediately:

Only generate from trusted, internally controlled OpenAPI specification sources. Disable or gate automatic generation from remote specs in CI/CD. Add validation/sanitization for x-ms-enum descriptions before generation. Review generated Python files for suspicious top-level statements near enum/model declarations. Run generation and validation in isolated environments without access to production secrets.

Remediation

Upgrade to Kiota 1.29.1, 1.32.0, or later.

Regenerate existing Python clients to replace previously generated vulnerable output.

Recommended validation after upgrade

Regenerate from the same spec used in proof-of-concept testing Confirm malicious multi-line enum descriptions no longer produce executable top-level output

Affected Packages

4 total 4 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetMicrosoft.OpenAPI.Kiota1.30.0&&< 1.32.01.32.0
.NETNuGetMicrosoft.OpenAPI.Kiota.Builder1.30.0&&< 1.32.01.32.0
.NETNuGetMicrosoft.OpenApi.Kiotaall versions1.29.1
.NETNuGetMicrosoft.OpenApi.Kiota.Builderall versions1.29.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. 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-7f3j-j7jj-r3vr is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-7f3j-j7jj-r3vr 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-7f3j-j7jj-r3vr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Code Generation Literal Injection in Kiota Python Generator Leads to Arbitrary Code Execution at Import Time. The Kiota Python code generator is vulnerable to a code generation literal injection issue when processing malicious or untrusted OpenAPI specifications. Specifically, attacker-controlled enum value descriptions from x-ms-enum.values[].description can flow into generated Python files without newline sanitization, allowing injected content to escape a comment context and execute at module scope when the generated module is imported. This issue requires user interaction in the form of
O3 Security · Impact-Aware SCA

Is GHSA-7f3j-j7jj-r3vr in your dependencies?

O3 detects GHSA-7f3j-j7jj-r3vr across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-7f3j-j7jj-r3vr: Microsoft.OpenAPI.Kiota… | O3 Security