What is the CVSS score of CVE-2026-59862?

CVE-2026-59862 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 1.0%.

Which versions of Microsoft Kiota are affected by CVE-2026-59862?

Microsoft Kiota Python client generator versions prior to 1.32.0 contain a code injection flaw that allows arbitrary Python code execution when developers generate client code from OpenAPI…. A patch is available.

How to fix or mitigate CVE-2026-59862?

Within 24 hours, identify all instances of Kiota Python client generator in use and review the sources of OpenAPI specifications being processed to assess exposure. Within 7 days, implement mandatory code review requirements for all OpenAPI descriptions, restrict code generation to exclusively trusted internal sources, and audit any recently generated client code for suspicious modifications or content. Within 30 days, monitor vendor advisories for patch availability; evaluate alternative Python client generation tools if waiting for a patch creates unacceptable business risk.

Microsoft Kiota CVE-2026-59862

EUVD-2026-44927 HIGH

Code Injection (CWE-94)

2026-07-16 GitHub_M

GHSA-7f3j-j7jj-r3vr

Python RCE Code Injection Kiota

7.5

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

8.8 HIGH

Attacker controls a remotely-fetched OpenAPI spec (AV:N, PR:N) but a developer must generate and import the client (UI:R); module-scope code execution yields full C:H/I:H/A:H.

3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Patch available

Jul 16, 2026 - 17:03 EUVD

Source Code Evidence Fetched

Jul 16, 2026 - 15:03 vuln.today

Analysis Generated

Jul 16, 2026 - 15:03 vuln.today

CVE Published

Jul 16, 2026 - 14:38 cve.org

HIGH 7.5

DescriptionCVE.org

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.32.0, Kiota's Python generator let attacker-controlled enum value descriptions from x-ms-enum.values[].description flow through KiotaBuilder.SetEnumOptions into Documentation.DescriptionTemplate and PythonConventionService.RemoveInvalidDescriptionCharacters without newline sanitization, allowing generated inline comments to split and execute attacker-controlled Python code at module scope when generated modules were imported. This issue is fixed in version 1.32.0.

AnalysisAI

Code injection in Microsoft Kiota's Python client generator (versions prior to 1.32.0) allows an attacker who controls an OpenAPI description to embed arbitrary Python that executes when a developer generates and imports the resulting client. The flaw stems from unsanitized x-ms-enum.values[].description strings being emitted as inline comments; embedded newlines break out of the comment and run at module scope. No public exploit identified at time of analysis, and the issue is not in CISA KEV. The assigned CVSS 3.1 base score is 7.5, though its impact metrics (C:N/I:N/A:H) understate what is functionally full code execution.

Technical ContextAI

Kiota is Microsoft's OpenAPI-based HTTP client code generator that turns an OpenAPI/Swagger description into typed client libraries across languages including Python. The vulnerability is a CWE-94 (Improper Control of Generation of Code / code injection) issue in the Python emitter. Kiota reads Microsoft's x-ms-enum vendor extension, whose values[].description fields carry human-readable enum documentation. These strings flow through KiotaBuilder.SetEnumOptions into Documentation.DescriptionTemplate and then PythonConventionService.RemoveInvalidDescriptionCharacters, which failed to strip or escape newline characters. Because Python line comments (#) terminate at a newline, a description containing an embedded newline splits the generated comment line, and any following text is emitted as live Python source at module top level, executing on import. The fix (PR #7735) sanitizes x-ms-enum descriptions before emitting comments/docstrings; a parallel Ruby injection via string interpolation markers was fixed in the same release (PR #7746).

RemediationAI

Vendor-released patch: 1.32.0 - upgrade Kiota to 1.32.0 or later before generating any further Python (or Ruby) clients, per advisory GHSA-7f3j-j7jj-r3vr (https://github.com/microsoft/kiota/security/advisories/GHSA-7f3j-j7jj-r3vr) and the v1.32.0 release notes (https://github.com/microsoft/kiota/releases/tag/v1.32.0). Where immediate upgrade is not possible, only generate clients from trusted, first-party OpenAPI descriptions and treat any externally-sourced spec as untrusted input; specifically, inspect or strip x-ms-enum values[].description fields for embedded newline/control characters before running the generator (trade-off: manual review does not scale and can miss obfuscated payloads). As a further control, review generated Python modules in code review before importing or running them, and generate in an isolated, non-privileged build sandbox so any injected code executes without access to production credentials (trade-off: adds build-pipeline friction). Regenerate any Python clients that were produced from untrusted specs with a patched version.