CVE-2026-42151

A flaw was found in Prometheus, an open-source monitoring system. The client_secret field within the Azure Active Directory (AD) remote write OAuth configuration was incorrectly handled as a plain string instead of a secure Secret type. This misconfiguration allowed any user or process with access to the /-/config HTTP API endpoint to view the Azure OAuth client secret in plaintext. This vulnerability leads to information disclosure, potentially compromising the security of integrated Azure AD services.

This Important information disclosure flaw in Prometheus affects instances configured to use Azure AD remote write with OAuth authentication. The client secret, intended to be a secure credential, is exposed in plaintext through the /-/config HTTP API endpoint. This could allow an attacker with access to this endpoint to retrieve the secret, potentially compromising integrated Azure AD services.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.