Vault token and secret values are exposed in thrown errors when using hashi-vault-js.

Every API method in Vault.js executes throw parseAxiosError(err), which returns the raw AxiosError untouched. That error carries the full Axios configuration, including the X-Vault-Token header and the request body. Consuming applications that log caught errors (e.g., using console.error, pino, winston, Sentry, or APMs) inadvertently log the live Vault token in plaintext. Furthermore, write-path methods expose submitted passwords and secret values via err.config.data.

When consuming applications log intercepted exceptions, sensitive credentials such as tokens, passwords, and secrets are unknowingly exposed to application logs, monitoring services, and APM systems via the raw AxiosError. This may lead to authorization bypass or unauthorized access to the underlying Vault instance.

This vulnerability should be addressed by redacting err.config.headers['X-Vault-Token'] and err.config.data before re-throwing, or by throwing a purpose-built error containing only safe properties like status and message. Users should upgrade to a version that includes this fix.

If users cannot immediately update the library, they can mitigate this issue by capturing all exceptions thrown by hashi-vault-js and sanitizing or omitting the err.config object before passing the errors to logging utilities or crash reporters.

hashi-vault-js would like to thank Sebastián Alba Vives for reporting this vulnerability.