Kestra: Unauthenticated RCE via /configs path-suffix auth-filter bypass

{
  "id": "d62263abae4f9f572cea892ffe5550d281bcc1ee09a44a013f28ef2cfc05129c",
  "url": "https://osv.dev/vulnerability/CVE-2026-53576",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Kestra: Unauthenticated RCE via /configs path-suffix auth-filter bypass",
    "summary": "Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the authentication filter for the REST API (@Filter(\"/api/v1/**\")) treats any request whose path ends in /configs as the public instance-config endpoint and forwards it without a credential check. kestra addresses its resources by URL path segments that the caller chooses (/api/v1/{tenant}/flows/{namespace}, /api/v1/{tenant}/executions/{namespace}/{id}, /api/v1/{tenant}/namespaces/{namespace}/kv/{key}). An anonymous caller picks the literal configs as the final segment, and the request bypasses Basic-Auth entirely. Because the bypass reaches the flow-create and execution-trigger routes, an unauthenticated caller creates a flow containing a Shell or Process task and runs it. The task executes as root inside the kestra container. The official docker-compose.yml mounts /var/run/docker.sock, so root in the container reaches the host Docker daemon. This vulnerability is fixed in 1.0.45 and 1.3.21.",
    "evidence": "osv:CVE-2026-53576",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-53576",
      "aliases": [
        "CVE-2026-53576",
        "GHSA-2q47-568g-9h4f"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/kestra-io/kestra",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "670b719eb5e0fc579ad9044551223642c24335dd"
                },
                {
                  "introduced": "1e670b5e7e92f89533ee17d564263578b0d5ec8c"
                },
                {
                  "fixed": "2541c53230388d76a9acc1b43245ebce31312a88"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:kestra:kestra:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.0.45"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:kestra:kestra:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.1.0"
                      },
                      {
                        "fixed": "1.3.21"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.0.44",
            "v1.3.20",
            "v1.0.43",
            "v1.3.19",
            "v1.0.42",
            "v1.3.18",
            "v1.0.41",
            "v1.3.17",
            "v1.0.40",
            "v1.3.16",
            "v1.0.39",
            "v1.3.15",
            "v1.0.38",
            "v1.3.14",
            "v1.3.13",
            "v1.0.37",
            "v1.3.11",
            "v1.0.36",
            "v1.3.9",
            "v1.0.35",
            "v1.3.8",
            "v1.3.7",
            "v1.0.34",
            "v1.3.6",
            "v1.3.5",
            "v1.3.4",
            "v1.0.33",
            "v1.3.3",
            "v1.3.2",
            "v1.0.32",
            "v1.0.31",
            "v1.3.1",
            "v1.0.30",
            "v1.3.0",
            "v1.3.0-rc1",
            "v1.0.29",
            "v1.3.0-rc0",
            "v1.0.28",
            "v1.0.27",
            "v1.0.26",
            "v1.0.25",
            "v1.0.24",
            "v1.0.23",
            "v1.0.22",
            "v1.0.21",
            "v1.0.20",
            "v1.0.19",
            "v1.0.18",
            "v1.0.17",
            "v1.0.16",
            "v1.0.15",
            "v1.0.14",
            "v1.0.13",
            "v1.0.12",
            "v1.0.11",
            "v1.0.10",
            "v1.0.9",
            "v1.0.8",
            "v1.0.7",
            "v1.0.6",
            "v1.0.5",
            "v1.0.4",
            "v1.0.3",
            "v1.0.2",
            "v1.0.1",
            "v1.0.0",
            "v0.0.1234",
            "v0.19.0",
            "v0.9.1",
            "v0.9.0",
            "v0.8.1",
            "v0.8.0",
            "v0.7.1",
            "v0.7.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53576.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.260326425Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53576.json",
        "https://github.com/kestra-io/kestra/security/advisories/GHSA-2q47-568g-9h4f",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53576"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-288",
          "CWE-94"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53576.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53576",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513397,
  "published_at": "2026-06-26T20:54:08.282+00:00"
}