CVE-2026-15815: 
Grafana vulnerability analysis and mitigation

CVE-2026-15815 is a path traversal and unsafe symbolic link resolution vulnerability in Grafana OSS and Grafana Enterprise that enables remote code execution via crafted plugin archives. Affected versions include Grafana OSS and Enterprise 11.6.0–11.6.17, 12.0.0–12.4.10, 13.0.0–13.0.8, 13.1.0–13.1.5, and 13.2.0–13.2.1. The vulnerability was published on September 17, 2026, with a patch released the same day. It carries a CVSS v3.1 base score of 8.8 (High) (GitHub Advisory, Feedly).

The root cause is improper resolution of symbolic links during plugin archive extraction (CWE-22: Path Traversal; CWE-59: Improper Link Resolution Before File Access; CWE-94: Code Injection). An attacker crafts a plugin archive containing chained relative symbolic link entries that, when extracted, escape the designated plugin installation directory and write arbitrary files — including an executable backend binary — to locations outside that directory. Critically, plugin archives are extracted before their signature is verified, meaning even a plugin with a valid signature cannot prevent the write if the archive itself is malicious. The attack can be triggered via grafana-cli, the GF_INSTALL_PLUGINS environment variable, or preinstall configuration (GitHub Advisory, Feedly).

Successful exploitation allows an attacker to write arbitrary files anywhere on the filesystem accessible to the Grafana server process, and to execute arbitrary code with the privileges of that process. This results in full confidentiality, integrity, and availability compromise of the Grafana server host, and may enable lateral movement within the network depending on the server's access and permissions. An operator can be affected simply by installing a plugin that appears legitimate from the Grafana plugin marketplace or any other source (GitHub Advisory, Feedly).

As of the time of disclosure, there is no public proof-of-concept exploit and no evidence of in-the-wild exploitation (Feedly). The EPSS score is 0.0, reflecting low current exploitation probability. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. No threat actor attribution has been reported. However, the attack vector is network-accessible and requires only user interaction (an operator installing a plugin), making it a realistic supply-chain-style attack scenario.

1. Craft a malicious plugin archive: Create a plugin archive (e.g., a .zip file) containing chained relative symbolic link entries (e.g., plugin/link1 -> ../../../, plugin/link2 -> link1/tmp/) designed to escape the Grafana plugin installation directory upon extraction.
2. Embed a malicious executable: Include a backend binary (e.g., a reverse shell or backdoor) within the archive, positioned so that the symlink chain causes it to be written to a directory outside the plugin folder (e.g., a cron directory, init script path, or other privileged location).
3. Distribute or deliver the plugin: Host the malicious archive on a web server, submit it to the Grafana plugin marketplace (if feasible), or socially engineer an operator into installing it via grafana-cli install <plugin-url>, the GF_INSTALL_PLUGINS environment variable, or preinstall configuration.
4. Trigger extraction: When the Grafana server processes the plugin installation, it extracts the archive without first verifying the signature, causing the symlink chain to resolve and write the malicious binary outside the plugin directory.
5. Achieve code execution: The dropped executable runs with the privileges of the Grafana server process, granting the attacker remote code execution on the host (GitHub Advisory, Feedly).

• File System: Unexpected files or executables written outside the Grafana plugin installation directory (e.g., in /tmp, /etc/cron.d/, /usr/local/bin/, or other system paths); symbolic links within the plugin directory pointing to locations outside it.
• Process: Unusual child processes spawned by the Grafana server process (e.g., /bin/bash, sh, curl, wget, python, or unknown binaries); new processes running with Grafana service account privileges.
• Logs: Grafana server logs showing plugin installation events followed by unexpected file system activity; errors or warnings during plugin extraction referencing symlink resolution.
• Network: Outbound connections from the Grafana server process to unexpected external IP addresses or domains, particularly after a plugin installation event.

Grafana released patched versions on September 17, 2026. Users should upgrade to Grafana OSS or Enterprise version 11.6.18+, 12.4.11+, 13.0.9+, 13.1.6+, or 13.2.2+ as applicable (GitHub Advisory, Grafana Advisory). As interim mitigations: restrict plugin installation to trusted operators only; avoid installing plugins from untrusted or unverified sources; disable automatic plugin installation via GF_INSTALL_PLUGINS or preinstall configuration if not required; and audit all currently installed plugins for legitimacy.