Path Traversal in Microsoft.OpenApi.Kiota (CVE-2026-59863)
Summary
Path traversal in Microsoft.OpenApi.Kiota (CVE-2026-59863). Risk of unauthorized operations or information disclosure. Exploitable via outputPath. Mitigation: upgrade to 1.29.1 or later.
Original description
The description as published by the source.
Summary
Microsoft Kiota honors a poisoned .kiota/workspace.json — the workspace configuration that Kiota's
documented team workflow has developers commit to their repository — unvalidated on
kiota client generate / kiota plugin generate. A repository (or pull request) containing a malicious
per-client / per-plugin outputPath causes Kiota, when a developer or CI runs the documented regenerate
command, to (CWE-22) write the entire generated client to an arbitrary path outside the workspace — the
outputPath was not confined to the workspace root and absolute paths were accepted.
Confirmed on Kiota 1.32.4 (KIOTA_CONFIG_PREVIEW=true, the self-contained linux-x64 release binary).
Details
// .kiota/workspace.json (committed to the repo)
"clients": { "MyClient": {
"outputPath": "/abs/path/outside/repo/pwned_client" // -> generated client written here (CWE-22)
}}
Running kiota client generate --client-name MyClient in the repo writes MyClient.cs,
P/PRequestBuilder.cs, … to the attacker-chosen outputPath (verified outside the working tree).
Note on descriptionLocation
The per-consumer descriptionLocation is intentionally fetched at generation time — this is how Kiota knows
where to pull an updated description from when refreshing a client, the same way any other value in a
committed lock/config file is honored. It is not treated as a vulnerability and is unchanged; only
outputPath is now confined.
Im…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59863 has been found in Microsoft.OpenApi.Kiota.
Attackers can target a specific entry point like outputPath over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Microsoft.OpenApi.Kiota to 1.29.1 or later.
If unsure, ask your IT team or search "Microsoft.OpenApi.Kiota CVE-2026-59863" on the vendor's site.
CVE-2026-59863 (Microsoft.OpenApi.Kiota) — CWE-22
Attack surface: outputPath / MyClient.cs / descriptionLocation
Patched: 1.29.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in Microsoft.OpenApi.Kiota. Attackers reach the vulnerable code path via outputPath.
Check the vendor advisory for the affected versions of Microsoft.OpenApi.Kiota. Attack surface: outputPath / MyClient.cs / descriptionLocation.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.29.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Microsoft.OpenApi.Kiota' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Microsoft.OpenApi.Kiota' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Microsoft.OpenApi.Kiotaを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Microsoft.OpenApi.Kiota to 1.29.1ステージング環境で 1.29.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com