---
id: "CVE-2026-119566"
kind: "vulnerability"
aliases: ["CVE-2026-119566"]
title: "Prometheus: remote_write redirects leak Azure AD and Google IAM bearer tokens"
severity: "medium"
cvss: 6.3
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["azure-ad", "google-iam", "prometheus", "remote-write", "runtime", "self-hosted"]
not_affected_if: ["no-azure-or-gcp-iam-auth", "no-remote-write", "trusted-endpoints-only"]
published_at: "2026-10-30T12:16:44+00:00"
first_seen_at: "2026-10-30T12:30:26+00:00"
updated_at: "2026-10-30T12:32:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119566", "first_seen_at": "2026-10-30T12:30:26+00:00"}]
---

# Prometheus: remote_write redirects leak Azure AD and Google IAM bearer tokens

Prometheus through 3.15.1 forwards its bearer token to whatever host a remote_write request is redirected to. An attacker who controls the remote-write endpoint or a redirecting server can return a 3xx response and capture the Azure AD or Google IAM token.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Prometheus version with `prometheus --version` and compare it with the fixed release.
- Look for `remote_write` blocks in the Prometheus config that use Azure AD or Google IAM authentication.
- Confirm whether remote_write endpoints are reached through hosts you do not control.

## Timeline

- 2026-10-30T12:30:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119566

## From the sources

Prometheus through 3.15.1 contains a credential leak vulnerability that allows attackers to capture Azure AD or Google IAM bearer tokens by redirecting remote_write requests to another host. Attackers controlling the remote-write endpoint or a redirecting server can return a 3xx to their host and replay the token, for example to write metrics to the victim's backend.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_