Security advisory

{
  "id": "bf330b2e9133cd71e5f52796a2217e95c514d7c1a50c57d52e5b56dad3467470",
  "url": "https://osv.dev/vulnerability/CVE-2021-36156",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-36156",
    "summary": "An issue was discovered in Grafana Loki through 2.2.1. The header value X-Scope-OrgID is used to construct file paths for rules files, and if crafted to conduct directory traversal such as ae ../../sensitive/path/in/deployment pathname, then Loki will attempt to parse a rules file at that location and include some of the contents in the error message.",
    "evidence": "osv:CVE-2021-36156",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-36156",
      "aliases": [
        "CVE-2021-36156",
        "GHSA-grj5-8x6q-hc9q"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/grafana/loki",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "babea82ef558c4b4dc685fd4ca677de1f0a7ee8f"
                },
                {
                  "fixed": "f5fd029660034d31833ff1d2620bb82d1c1618af"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:grafana:loki:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.2.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "f5fd029660034d31833ff1d2620bb82d1c1618af"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2.3.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.2.0",
            "v2.2.1",
            "v2.0.0",
            "v1.6.0",
            "v1.5.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0",
            "v0.4.0",
            "v0.3.0",
            "v0.2.0",
            "v1.0.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-36156.json"
          }
        }
      ],
      "modified": "2026-10-20T10:55:02.616212417Z",
      "provider": "osv",
      "references": [
        "https://github.com/grafana/loki/pull/4020#issue-694377133",
        "https://github.com/grafana/loki/releases/tag/v2.3.0"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-36156",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386765,
  "published_at": "2021-08-03T15:15:08.623+00:00"
}