{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/grafana-mcp-server-0.17.1-and-prior/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.6,"id":"CVE-2026-15583"},{"cvss":7.5,"id":"CVE-2026-21729"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Grafana MCP Server 0.17.1 and prior","Grafana Loki 3.7.0 and prior"],"_cs_severities":["high"],"_cs_tags":["grafana","ssrf","dos","vulnerability","cve"],"_cs_type":"advisory","_cs_vendors":["Grafana Labs"],"content_html":"\u003cp\u003eOn July 15, 2026, Grafana Labs released security advisories concerning critical vulnerabilities affecting Grafana MCP Server and Grafana Loki. CVE-2026-15583, a server-side request forgery (SSRF) vulnerability, was identified in Grafana MCP Server versions 0.17.1 and prior, stemming from improper validation of the \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header. This flaw could allow an attacker to bypass access controls and potentially access internal network resources. Concurrently, CVE-2026-21729, an unbounded memory allocation vulnerability, was found in Grafana Loki versions 3.7.0 and prior. This issue arises when processing specific \u003ccode\u003edetected_fields\u003c/code\u003e queries, which can lead to excessive memory consumption and ultimately result in a denial of service (DoS) for the Loki instance. Defenders should prioritize updating these products to prevent potential data exfiltration, unauthorized internal access, or service disruption.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003e\u003cstrong\u003eInitial Access (CVE-2026-15583 - SSRF):\u003c/strong\u003e An unauthenticated attacker sends a specially crafted HTTP request to a vulnerable Grafana MCP Server instance.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eHeader Manipulation:\u003c/strong\u003e The attacker includes an \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header in the request containing a URL pointing to an internal resource or a sensitive external service that the Grafana server can access.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eSSRF Trigger:\u003c/strong\u003e The vulnerable Grafana MCP Server processes the malformed \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header without proper validation.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eInternal Network Access:\u003c/strong\u003e The server then makes a request to the URL specified in the \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header, effectively bypassing external network controls and accessing internal services or data that should not be publicly exposed.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eInformation Disclosure/Further Exploitation:\u003c/strong\u003e The attacker receives the response from the internal service, potentially exfiltrating sensitive data, interacting with internal APIs, or leveraging other vulnerabilities found within the internal network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cem\u003e(CVE-2026-21729 - DoS)\u003c/em\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\u003cstrong\u003eCrafted Query:\u003c/strong\u003e An attacker sends a malicious \u003ccode\u003edetected_fields\u003c/code\u003e query to a vulnerable Grafana Loki instance.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eUnbounded Memory Allocation:\u003c/strong\u003e The Loki server attempts to process the crafted query, which triggers an unbounded memory allocation issue.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eResource Exhaustion:\u003c/strong\u003e Loki consumes an excessive amount of system memory, leading to resource exhaustion.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eService Disruption:\u003c/strong\u003e The Loki instance becomes unresponsive or crashes, resulting in a denial of service for legitimate users.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe identified vulnerabilities pose significant risks to organizations utilizing Grafana MCP Server and Grafana Loki. Successful exploitation of CVE-2026-15583 (SSRF) could allow attackers to bypass network perimeter defenses, enabling them to access internal systems, services, and sensitive data that are not directly exposed to the internet. This could lead to data breaches, unauthorized configuration changes, or further lateral movement within the compromised network. For CVE-2026-21729 (DoS), successful exploitation would render the Grafana Loki instance unavailable, disrupting logging and monitoring capabilities. While no specific victim counts or sectors were disclosed, these types of vulnerabilities are routinely targeted across all industries, impacting the availability and confidentiality of critical data.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately patch Grafana MCP Server instances to a version greater than 0.17.1 to remediate CVE-2026-15583 and prevent server-side request forgery.\u003c/li\u003e\n\u003cli\u003eImmediately patch Grafana Loki instances to a version greater than 3.7.0 to remediate CVE-2026-21729 and prevent denial of service attacks.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;Detect CVE-2026-15583 Exploitation - Grafana MCP Server SSRF Attempt\u0026quot; to your SIEM to detect attempts to exploit the SSRF vulnerability via the \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header.\u003c/li\u003e\n\u003cli\u003eEnable comprehensive web server logging, particularly for HTTP headers, to ensure visibility of suspicious \u003ccode\u003eX-Grafana-URL\u003c/code\u003e header usage.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-16T18:22:40Z","date_published":"2026-07-16T18:22:40Z","id":"https://feed.craftedsignal.io/briefs/2026-07-grafana-mcp-loki-vulnerabilities/","summary":"Grafana has published security advisories for vulnerabilities in Grafana MCP Server (CVE-2026-15583), leading to server-side request forgery, and Grafana Loki (CVE-2026-21729), resulting in unbounded memory allocation and denial of service, impacting versions 0.17.1 and prior for MCP Server and 3.7.0 and prior for Loki, urging users to update to mitigate potential exploitation.","title":"Grafana MCP Server SSRF and Loki DoS Vulnerabilities Addressed","url":"https://feed.craftedsignal.io/briefs/2026-07-grafana-mcp-loki-vulnerabilities/"}],"language":"en","title":"CraftedSignal Threat Feed - Grafana MCP Server 0.17.1 and Prior","version":"https://jsonfeed.org/version/1.1"}