MinIO is Vulnerable to SSE Metadata Injection via Replication Headers

{
  "id": "332ec8a68a1d45afade686b28348f29c72cdc00e7756bd1cdb2f52fe83f043e9",
  "url": "https://osv.dev/vulnerability/GHSA-3rh2-v3gr-35p9",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MinIO is Vulnerable to SSE Metadata Injection via Replication Headers",
    "summary": "## Impact _What kind of vulnerability is it? Who is impacted?_ A flaw in `extractMetadataFromMime()` allows any authenticated user with `s3:PutObject` permission to inject internal server-side encryption metadata into objects by sending crafted `X-Minio-Replication-*` headers on a normal PutObject request. The server unconditionally maps these headers to `X-Minio-Internal-*` encryption metadata without verifying that the request is a legitimate replication request. Objects written this way carry bogus encryption keys and become **permanently unreadable** through the S3 API. Any authenticated user or service with `s3:PutObject` permission on any bucket can make objects permanently unreadable by injecting fake SSE encryption metadata. The attacker sends a standard PutObject request with `X-Minio-Replication-Server-Side-Encryption-*` headers but **without** the `X-Minio-Source-Replication-Request` header that marks legitimate replication traffic. The server maps these headers to internal encryption metadata (`X-Minio-Internal-Server-Side-Encryption-Sealed-Key`, etc.), causing all subsequent GetObject and HeadObject calls to treat the object as encrypted with keys that do not exist. This is a targeted denial-of-service vulnerability. An attacker can selectively corrupt individual objects or entire buckets. The `ReplicateObjectAction` IAM permission is never checked because the request is a normal PutObject, not a replication request. **Affected component:** `cmd/handler-utils.go`",
    "evidence": "osv:GHSA-3rh2-v3gr-35p9",
    "products": [
      {
        "name": {
          "value": "github.com/minio/minio",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-3rh2-v3gr-35p9",
      "aliases": [
        "CVE-2026-34204",
        "GHSA-3rh2-v3gr-35p9",
        "GO-2026-4896"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H"
        },
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-20240328174456-468a9fae83e9"
                },
                {
                  "last_affected": "0.0.0-20260212201848-7aac2a2c5b7c"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/minio/minio",
            "purl": "pkg:golang/github.com/minio/minio",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-3rh2-v3gr-35p9/GHSA-3rh2-v3gr-35p9.json"
          }
        }
      ],
      "modified": "2026-10-08T08:11:01.800046379Z",
      "provider": "osv",
      "references": [
        "https://github.com/minio/minio/security/advisories/GHSA-3rh2-v3gr-35p9",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-34204",
        "https://docs.min.io/enterprise/aistor-object-store/upgrade-aistor-server/community-edition",
        "https://github.com/minio/minio"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-287"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": "2026-03-31T20:16:28Z",
        "github_reviewed_at": "2026-03-27T22:26:05Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-34204",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 98756,
  "published_at": "2026-03-27T22:26:05+00:00"
}