# CVE-2026-75889: Grafana Alloy arbitrary file read via ServiceMonitor bearerTokenFile

Source: https://junglewise.ai/threats/cve-2026-75889-grafana-alloy-arbitrary-file-read-via-servicemonitor  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-27. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-75889 · Severity: high · CVSS 7.7 · Published 2026-08-27

Grafana Alloy is an observability agent that collects metrics from Kubernetes clusters. An attacker with write access to ServiceMonitor resources can trick Alloy into reading arbitrary files from the system—including its Kubernetes service account token—and sending the contents to an attacker-controlled server. This could allow an attacker to escalate privileges within Kubernetes and access sensitive data.

Vendors: [Grafana](https://junglewise.ai/threats/vendors/grafana).

## Quick answers

**Is CVE-2026-75889 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-75889 being exploited in the wild.

**How severe is CVE-2026-75889?** High severity, with a CVSS score of 7.7, published 27 August 2026.

**Which products and versions are affected?** Grafana Alloy <1.19.0.

**Is there a fix for CVE-2026-75889?** A patch was published on 2026-08-27: Fixed in version 1.19.0 and later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-75889 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-75889?** Check whether you run Grafana Alloy 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 in the prometheus.operator.servicemonitors component of Grafana Alloy. It fails to validate the bearerTokenFile parameter in ServiceMonitor resources, allowing a user with ServiceMonitor write permissions to specify arbitrary local file paths. When Alloy processes such a ServiceMonitor, it reads the specified file and sends its contents as a bearer token to the scrape endpoint specified in the resource. An attacker can control the scrape endpoint to capture the file contents. The attack vector is network-accessible via Kubernetes ServiceMonitor resources, requiring ServiceMonitor write access but no higher privileges than Alloy itself. The fix is available in Alloy version 1.19.0 and later.

## Affected products

- Grafana Alloy <1.19.0

## Timeline

- 2026-08-27: disclosed
- 2026-08-27: patched: Fixed in version 1.19.0 and later

## References

- [https://grafana.com/security/security-advisories/cve-2026-75889](https://grafana.com/security/security-advisories/cve-2026-75889)