Grafana SSRF via Unvalidated Request Header Control

A caller-supplied X-Grafana-URL request header controls the destination of mcp-grafana's outbound requests, and the grafana_api_request tool lets the caller also choose the HTTP method, path, and body. Because the destination is not restricted to the configured Grafana instance, a caller can direct requests at internal, loopback, and link-local network services (including metadata endpoints) and read the responses, resulting in server-side request forgery. The fix for CVE-2026-15583 prevented the configured service-account token from being sent to unintended destinations but did not restrict the destinations themselves.

Casky was already ahead

This CVE exploits attack patterns that Casky's 331matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

This critical vulnerability (CVSS 9.1) affects mcp-grafana's request handling, where an attacker can manipulate the X-Grafana-URL header to redirect outbound requests to arbitrary destinations—including internal services, loopback addresses, and cloud metadata endpoints. By combining header manipulation with control over HTTP methods, paths, and request bodies through the grafana_api_request tool, attackers can conduct server-side request forgery (SSRF) attacks to exfiltrate sensitive data from restricted network segments. This affects any organization deploying mcp-grafana without proper input validation, particularly those exposing the tool in multi-tenant or untrusted environments where attackers could pivot from initial access to internal reconnaissance.

Casky's 331 matched skills leverage Claude's extended reasoning to detect the attack patterns underlying TA0001 (Reconnaissance) and TA0006 (Resource Development) techniques. Practitioners using Casky will identify suspicious patterns such as: repeated X-Grafana-URL headers pointing to non-Grafana hosts, requests to 169.254.169.254 or 127.0.0.1 metadata services, abnormal HTTP methods paired with sensitive paths, and responses containing credential material or internal configuration data. The platform's CWE-918 mapping ensures detection of request path traversal and destination validation bypasses, surfacing findings that correlate header manipulation attempts with network reconnaissance signatures—enabling security teams to distinguish malicious SSRF probes from legitimate Grafana API calls before data exfiltration occurs.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

331 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-19516.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0006

Investigate the attack patterns behind CVE-2026-19516

Casky has 331 skills that investigate the attack patterns behind CVE-2026-19516. Run one and get CVSS-scored findings in 3 minutes.

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