CyberSecBulletin
CVE-2026-15583NVD status: Awaiting Analysis

Grafana MCP Server: Externally Controlled Reference to a Resource in Another Sphere

CVE-2026-15583 is a high-severity externally controlled reference to a resource in another sphere vulnerability in Grafana MCP Server from Grafana, with a CVSS 3.1 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Grafana MCP Server versions: 0.17.1 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Grafana MCP Server you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on grafana.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
GrafanaGrafana MCP Server0.17.1 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N. Scored by CNA (grafana.com).

Official description

A confused-deputy flaw in Grafana MCP Server allows an unauthenticated remote attacker to exfiltrate the server's environment-configured Grafana service-account token by supplying a crafted X-Grafana-URL request header. This also enables SSRF against arbitrary internal services, including cloud metadata endpoints.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Externally Controlled Reference to a Resource in Another Sphere

The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.

More Externally Controlled Reference to a Resource in Another Sphere vulnerabilities (CWE-610)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Grafana MCP Server

All Grafana MCP Server vulnerabilities

Recent Externally Controlled Reference to a Resource in Another Sphere vulnerabilities

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