Kiota, an OpenAPI‑based HTTP client generator, incorrectly copies the oauth_card_path from an OpenAPI spec into a generated API plugin manifest without sanitizing the value. An attacker who supplies a maliciously crafted specification can cause the reference to point to a parent‑directory, a rooted path or an absolute URI. When a consuming host resolves the reference, it may cross the intended plugin‑package boundary or use an unintended authentication card, potentially exposing sensitive information or granting unauthorized credential usage. This flaw does not allow Kiota itself to read a file or execute code during generation, but it creates a vulnerability that can be exercised by any downstream consumer that resolves the unsafe reference.

The issue affects Microsoft.OpenApi.Kiota, Microsoft.OpenApi.Kiota.Builder, and kiota packages from version 1.25.1 through 1.35.0. Version 1.35.0 includes the fix that validates the oauth_card_path reference before copying it into the manifest.

The CVSS score of 3.1 reflects the low severity of the flaw; the EPSS score is 1%, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is the supply of a malicious OpenAPI description to Kiota, which then generates a manifest containing an unsafe reference. Exploitation requires a downstream consumer to resolve that reference, so the risk is limited to environments that download and use plugin manifests from untrusted sources.