CVE-2026-59864Patch

LOWCVSS 9.3 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.5, `kiota plugin add` and `kiota plugin generate` (with `-t APIPlugin`) emitted attacker-controlled static_template.file values from x-ai-adaptive-card and x-ai-capabilities into generated Microsoft 365 Copilot and Teams plugin manifests without path validation, allowing ../, absolute, rooted, UNC, Windows drive, or URI paths in response_semantics.static_template.file to cause path traversal or out-of-package file inclusion when the generated plugin was deployed. This issue is fixed in version 1.29.1 and 1.32.5.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-22CWE-829

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-16: 1Patch / Workaround · 2026-07-16: 1Technical Details · 2026-07-16: 107-16
Signal classification1 categories
Patch
1100.0%
Full discourse1 post
  • Upwind Security MDR@UpwindMDR
    Patch

    🚨Critical - Three Microsoft Kiota flaws from untrusted OpenAPI specs (CVE-2026-59864 / 59865 / 59866) Microsoft Kiota, the OpenAPI-based client and Copilot/Teams plugin generator, has three critical vulnerabilities before 1.32.5, all rooted in trusting attacker-controlled fields in an OpenAPI or plugin description (CVSS 9.3 each). - CVE-2026-59866: unsanitized clientClassName / clientNamespaceName during kiota generate enable path traversal outside the output directory and code injection into generated class/namespace declarations. - CVE-2026-59865: kiota info presents a spec-supplied dependencyInstallCommand as its recommended install command, leading to command injection when run. - CVE-2026-59864: kiota plugin add/generate write attacker-controlled static_template.file paths into Copilot/Teams manifests without validation, allowing path traversal / out-of-package file inclusion. All are triggered by running Kiota against a malicious OpenAPI/plugin description. Three separate bugs, one fix. 👉Upgrade Microsoft Kiota to 1.32.5 or later.

    Post summary

    Microsoft Kiota 1.32.5 or newer includes a fix for three critical vulnerabilities (CVE‑2026‑59864/65/66) that allow path traversal, command injection, and code injection via malicious OpenAPI/plugin specs.

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