CVE-2026-47249: Klever-Go KVM Hash-array Amplification Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w342-mj6g-v9c4",
  "modified" : "2026-06-05T15:27:42Z",
  "published" : "2026-06-05T15:27:42Z",
  "aliases" : [ "CVE-2026-47249" ],
  "summary" : "Klever-Go KVM: Hash-array amplification in P2P resolver request handling",
  "details" : "### Summary\nA connected peer can send a compressed `RequestDataType_HashArrayType` direct request that is only `442` bytes on the wire but expands into `200000` decoded hash entries inside the resolver path. On `klever-go` `v1.7.17`, this allows remote memory and CPU amplification against nodes that accept P2P peer connections.\n\n### Details\nResolver antiflood logic accounts only one logical message and the compressed wire size in `data/retriever/resolvers/messageProcessor.go#L30`.\n\n`Batch.Decompress()` in `data/batch/batch.go#L122` enforces an inflated byte cap but does not enforce a decoded repeated-field item cap. After decompression, `TxResolver` preallocates and iterates all decoded hashes in `data/retriever/resolvers/transactionResolver.go#L194`, and `TrieNodeResolver` iterates the same unchecked decoded set in `data/retriever/resolvers/trieNodeResolver.go#L108`.\n\nPinned references:\n- https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/messageProcessor.go#L30\n- https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/batch/batch.go#L122\n- https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/transactionResolver.go#L194\n- https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/trieNodeResolver.go#L108\n\nThis appears distinct from the public `CVE-2026-44697` / `GHSA-87m7-qffr-542v`, which covered `MultiDataInterceptor` compressed batch fan-in. This report concerns resolver request paths that remain reachable through real libp2p direct-send plumbing on `v1.7.17`.\n\n### PoC\nReproduced with:\n\n```bash\ngo run auditpoc/request_batch_hash_amplification_poc.go\ngo test github.com/klever-io/klever-go/auditpoc -run TestRequestBatchHashAmplification_DirectSendReachability -count=1\n```\n\nObserved output:\n\n```text\nrequest wire bytes: 442\nfits direct-send limit (983040 bytes): true\ntx resolver lookups: 200000\ntrie resolver lookups: 200000\nheap delta before first tx lookup: 17.47 MiB\nok   github.com/klever-io/klever-go/auditpoc\n```\n\nThe E2E harness registers the victim resolver on the request topic and sends the malicious payload through `SendToConnectedPeer()` to prove the work amplification survives the real direct-send path.\n\n### Impact\nA connected peer can convert a sub-kilobyte request into large decode-time memory pressure and synchronous CPU work on the target node. Repeated requests or several concurrent peers can degrade or exhaust validator resources, affecting node availability.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/klever-io/klever-go"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.18"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/klever-io/klever-go/security/advisories/GHSA-w342-mj6g-v9c4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/klever-io/klever-go"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/klever-io/klever-go/releases/tag/v1.7.18"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-05T15:27:42Z",
    "nvd_published_at" : null
  }
}