Arc Enterprise cluster replication accepts unauthenticated MsgReplicateSync messages, enabling cluster-wide data injection from any TLS-trusted peer

{
  "id": "d17f861072e1d2f4a844a7191088348000acf7c5b74d623b5ed9d7813bc63dd1",
  "url": "https://osv.dev/vulnerability/CVE-2026-48106",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Arc Enterprise cluster replication accepts unauthenticated MsgReplicateSync messages, enabling cluster-wide data injection from any TLS-trusted peer",
    "summary": "Arc is an open, SQL-native time-series database for telemetry. Prior to version 26.06.1, Arc Enterprise's cluster replication receiver at `internal/cluster/replication/receiver.go` validates only the wire-format envelope (length, opcode) of inbound messages. The `MsgReplicateSync` payload itself is accepted without any application-layer authentication — no HMAC, no signature, no per-message nonce. The replication stream is protected at the transport layer by TLS / mTLS, but there is no protection against application-layer message tampering or replay once a peer is on the cluster network. This is fixed in 2026.06.1. Some workarounds are available. Restrict cluster network access to known-trusted peers via strict firewall rules, audit replication logs for unexpected `MsgReplicateSync` traffic, and/or disable cluster mode until the fix is available.",
    "evidence": "osv:CVE-2026-48106",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-48106",
      "aliases": [
        "CVE-2026-48106",
        "GHSA-wfgr-8x84-22q7"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/basekick-labs/arc",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "8038f6f80f77bb48dbaa220e7415957be3988eff"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "26.06.1"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v26.05.1",
            "v26.04.1",
            "v26.03.2",
            "v26.03.1",
            "v26.02.2",
            "v26.02.1",
            "v26.01.2",
            "v26.01.1",
            "v25.12.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48106.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:28.329601700Z",
      "provider": "osv",
      "references": [
        "https://github.com/Basekick-Labs/arc/security/advisories/GHSA-wfgr-8x84-22q7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48106.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-48106"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-306",
          "CWE-345",
          "CWE-924"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "2026.06.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "2026.06.1"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48106.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-48106",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494787,
  "published_at": "2026-08-21T22:49:12.016+00:00"
}