{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:grafana:loki:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.6.4"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "d80526692af3bf28c35622a59a3231933b193bc2"
            }
          ],
          "repo": "https://github.com/grafana/loki",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "GRAFANA",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21726.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "2.3.0"
          },
          {
            "fixed": "3.5.9"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "The CVE-2021-36156 fix validates the namespace parameter for path traversal sequences after a single URL decode, by double encoding, an attacker can read files at the Ruler API endpoint /loki/api/v1/rules/{namespace}\n\nThanks to Prasanth Sundararajan for reporting this vulnerability.",
  "id": "CVE-2026-21726",
  "modified": "2026-07-17T03:42:02.910734408Z",
  "published": "2026-04-15T19:24:31.268Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21726.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://grafana.com/security/security-advisories/cve-2026-21726"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-21726"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Loki Path Traversal - CVE-2021-36156 Bypass"
}