Path Traversal in Microsoft.OpenApi.Kiota (CVE-2026-59864)
Summary
Path traversal in Microsoft.OpenApi.Kiota (CVE-2026-59864). Risk of unauthorized operations or information disclosure. Exploitable via static_template.file. Mitigation: upgrade to 1.29.1 or later.
Original description
The description as published by the source.
Summary
kiota plugin add / kiota plugin generate (with -t APIPlugin) emits an attacker-controlled static_template.file path from the AI-plugin extensions (x-ai-adaptive-card, x-ai-capabilities) verbatim, with no path validation, into the generated Microsoft 365 Copilot / Teams plugin manifest (-apiplugin.json). An attacker-controlled or compromised OpenAPI description can therefore embed a ../ / absolute path into the manifest's response_semantics.static_template.file, yielding a path traversal (CWE-22) / out-of-package file inclusion (CWE-829) that is resolved by the AI host when the generated plugin is deployed.
Confirmed on Kiota 1.32.4 (KIOTA_CONFIG_PREVIEW=true, the self-contained linux-x64 release binary).
Details
Both extension paths write the static_template.file reference straight into the manifest without sanitization — PluginsGenerationService.GetResponseSemanticsFromAdaptiveCardExtension mints static_template = {"file": }, and the x-ai-capabilities path copies the static_template object through:
# spec -> generated manifest (functions[].capabilities.response_semantics)
x-ai-adaptive-card: {title: T, data_path: $.x,
file: "../../../../../../etc/passwd"} -> static_template.file = "../../../../../../etc/passwd" (CWE-22)
x-ai-capabilities.response_semantics.static_template:
{file: "../../../../../../etc/passwd"} -> static_t…
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-2026-59864 has been found in Microsoft.OpenApi.Kiota.
Attackers can target a specific entry point like static_template.file 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-2026-59864" on the vendor's site.
CVE-2026-59864 (Microsoft.OpenApi.Kiota) — CWE-22
Attack surface: static_template.file / response_semantics.static_template.file / static_template / title
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 static_template.file.
Check the vendor advisory for the affected versions of Microsoft.OpenApi.Kiota. Attack surface: static_template.file / response_semantics.static_template.file / static_template / title.
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