# CVE-2026-119566: Prometheus remote_write credential leak via cross-host redirects

Source: https://junglewise.ai/threats/cve-2026-119566-prometheus-through-3-15-1-contains-a-credential-leak  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-30. Updated: 2026-10-30  
License: CC BY 4.0 with a link back

CVE-2026-119566 · Severity: medium · CVSS 4.8 · Published 2026-10-30

Prometheus, an open-source monitoring and metrics collection system, leaks Azure AD and Google IAM authentication bearer tokens when remote_write requests are redirected to attacker-controlled servers. An attacker who controls the remote-write endpoint or a redirecting intermediary can capture live credentials and use them to write metrics to or access the victim's cloud monitoring backend, potentially leading to data manipulation or unauthorized access.

Technologies: [Prometheus](https://junglewise.ai/threats/technologies/prometheus). Vendors: [Prometheus](https://junglewise.ai/threats/vendors/prometheus).

## Quick answers

**Is CVE-2026-119566 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-119566 being exploited in the wild.

**How severe is CVE-2026-119566?** Medium severity, with a CVSS score of 4.8, published 30 October 2026.

**Which products and versions are affected?** Prometheus through 3.15.1.

**Is there a fix for CVE-2026-119566?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-119566 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-119566?** Check whether you run Prometheus at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists because Azure AD and Google IAM authentication wrappers in Prometheus's remote_write client re-add the Authorization header on every hop during HTTP redirects, bypassing the credential-stripping logic introduced in prometheus/common v0.69.0. When follow_redirects is true (the default), a 3xx redirect response from the remote_write URL to an attacker-controlled host will forward the bearer token. This affects only configurations that explicitly set remote_write with azuread or google_iam authentication.

## Affected products

- Prometheus Prometheus through 3.15.1

## Timeline

- 2026-10-30: disclosed

## References

- [https://abraxaslabs.tech/research/prometheus-bearer-redirect](https://abraxaslabs.tech/research/prometheus-bearer-redirect)
- [https://github.com/prometheus/common/pull/901](https://github.com/prometheus/common/pull/901)

## Related threats

- [Prometheus stored XSS in legacy web UI heatmap chart](https://junglewise.ai/threats/cve-2026-44903-prometheus-stored-xss-in-legacy-web-ui-heatmap-chart)
- [Prometheus denial of service via memory exhaustion in remote read endpoint](https://junglewise.ai/threats/cve-2026-42154-prometheus-denial-of-service-via-memory-exhaustion-in-remote-read)
- [Prometheus information disclosure in Azure AD OAuth configuration](https://junglewise.ai/threats/cve-2026-42151-prometheus-information-disclosure-in-azure-ad-oauth-configuration)
- [Prometheus basic authentication bypass in exporter-toolkit](https://junglewise.ai/threats/prometheus-basic-authentication-bypass-in-exporter-toolkit-f8e091e2)