# CVE-2026-59863: Kiota: Workspace-config poisoning: out-of-repo file write + generation-time SSRF

> Attackers can write files outside the workspace via poisoned config, potentially leading to code execution on developer or CI hosts.

- **Severity:** High 7.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 16 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** GHSA-4rj6-vrwv-wr8m

## What is CVE-2026-59863?

CVE-2026-59863 is a high-severity path traversal vulnerability in microsoft kiota, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.5, Kiota honored a poisoned .kiota/workspace.json workspace configuration without validating per-client or per-plugin outputPath values during kiota client generate and kiota plugin generate, allowing a malicious repository or pull request to use absolute paths, rooted POSIX / paths, UNC \\ or // paths, Windows drive X:\ paths, or .. traversal segments to write generated client files outside the workspace root on a developer or CI host. This issue is fixed in version 1.29.1 and 1.32.5.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-59863?

8 open source packages ship an affected version, including Microsoft.OpenApi.Kiota and Microsoft.OpenApi.Kiota.Builder.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Microsoft.OpenApi.Kiota` | NuGet | All versions | 1.29.1 |
| `Microsoft.OpenApi.Kiota` | NuGet | All versions | 1.29.1 |
| `Microsoft.OpenApi.Kiota` | NuGet | From 1.30.0 | 1.32.5 |
| `Microsoft.OpenApi.Kiota` | NuGet | From 1.30.0 | 1.32.5 |
| `Microsoft.OpenApi.Kiota.Builder` | NuGet | All versions | 1.29.1 |
| `Microsoft.OpenApi.Kiota.Builder` | NuGet | All versions | 1.29.1 |
| `Microsoft.OpenApi.Kiota.Builder` | NuGet | From 1.30.0 | 1.32.5 |
| `Microsoft.OpenApi.Kiota.Builder` | NuGet | From 1.30.0 | 1.32.5 |

## How do I fix CVE-2026-59863?

Upgrade Microsoft.OpenApi.Kiota to a fixed version for your release line: 1.29.1 or 1.32.5.

## Is CVE-2026-59863 being exploited?

There is no known exploitation of CVE-2026-59863 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59863 and fix it if it is affected.

What it is: CVE-2026-59863 is a high-severity path traversal vulnerability in microsoft kiota, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-59863 in the wild and no public exploit code.

Affected packages and fixed versions:
- Microsoft.OpenApi.Kiota (NuGet): affected all versions; fixed in 1.29.1
- Microsoft.OpenApi.Kiota (NuGet): affected all versions; fixed in 1.29.1
- Microsoft.OpenApi.Kiota (NuGet): affected from 1.30.0; fixed in 1.32.5
- Microsoft.OpenApi.Kiota (NuGet): affected from 1.30.0; fixed in 1.32.5
- Microsoft.OpenApi.Kiota.Builder (NuGet): affected all versions; fixed in 1.29.1
- Microsoft.OpenApi.Kiota.Builder (NuGet): affected all versions; fixed in 1.29.1
- Microsoft.OpenApi.Kiota.Builder (NuGet): affected from 1.30.0; fixed in 1.32.5
- Microsoft.OpenApi.Kiota.Builder (NuGet): affected from 1.30.0; fixed in 1.32.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-59863/ (Markdown: https://insights.sbomify.com/CVE-2026-59863/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59863
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59863
- OSV: https://osv.dev/vulnerability/CVE-2026-59863

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59863/
Summaries are generated and may contain mistakes; the official description above is the record.