CVE-2026-119566

A flaw was found in Prometheus. This vulnerability allows an attacker who controls a configured remote write endpoint or redirecting server to cause an information disclosure. By returning an HTTP redirect response to an arbitrary host, the server can induce Prometheus into forwarding sensitive authentication bearer tokens used for cloud services. An attacker can capture and replay these leaked credentials to perform unauthorized actions against target backend systems.

This vulnerability is rated as Moderate severity for Red Hat products because successful exploitation requires specific remote write configurations using cloud bearer authentication and an adversary capable of manipulating HTTP routing or controlling the remote endpoint. In default Red Hat deployments, Prometheus remote write forwarding is not configured or enabled out of the box. Environments that do not export metrics to external infrastructure or that do not utilize cloud-provider bearer tokens are not exposed to this credential exposure.

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.