Klever-Go KVM: Hash-array amplification in P2P resolver request handling

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Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.18, the P2P resolver request handling logic is vulnerable to hash-array amplification. A connected peer can send a compressed RequestDataType_HashArrayType direct request that is only 442 bytes on the wire but expands into 200,000 decoded hash entries inside the resolver path. The resolver's antiflood logic counts only a single logical message and the compressed wire size, and while Batch.Decompress() caps the decompressed byte size, it never limits the number of decoded repeated-field items. As a result, both TxResolver and TrieNodeResolver preallocate and iterate over the entire unchecked set of decoded hashes, causing remote memory and CPU amplification against any node that accepts P2P peer connections. This issue is fixed in version 1.7.18.

Source published

7 Aug 2026 22:09:03 UTC

Source modified

10 Aug 2026 14:07:38 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.18, the P2P resolver request handling logic is vulnerable to hash-array amplification. A connected peer can send a compressed RequestDataType_HashArrayType direct request that is only 442 bytes on the wire but expands into 200,000 decoded hash entries inside the resolver path. The resolver's antiflood logic counts only a single logical message and the compressed wire size, and while Batch.Decompress() caps the decompressed byte size, it never limits the number of decoded repeated-field items. As a result, both TxResolver and TrieNodeResolver preallocate and iterate over the entire unchecked set of decoded hashes, causing remote memory and CPU amplification against any node that accepts P2P peer connections. This issue is fixed in version 1.7.18.

Source published

Aug 7, 2026, 10:09:03 PM (timezone not stated)

Source modified

Aug 10, 2026, 2:07:38 PM (timezone not stated)

Observed here

7 Nov 2026 10:40:18 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.18, the P2P resolver request handling logic is vulnerable to hash-array amplification. A connected peer can send a compressed RequestDataType_HashArrayType direct request that is only 442 bytes on the wire but expands into 200,000 decoded hash entries inside the resolver path. The resolver's antiflood logic counts only a single logical message and the compressed wire size, and while Batch.Decompress() caps the decompressed byte size, it never limits the number of decoded repeated-field items. As a result, both TxResolver and TrieNodeResolver preallocate and iterate over the entire unchecked set of decoded hashes, causing remote memory and CPU amplification against any node that accepts P2P peer connections. This issue is fixed in version 1.7.18.

Source published

7 Aug 2026 23:17:03 UTC

Source modified

23 Oct 2026 20:10:00 UTC

Observed here

25 Oct 2026 12:17:20 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

### Summary A 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. ### Details Resolver antiflood logic accounts only one logical message and the compressed wire size in `data/retriever/resolvers/messageProcessor.go#L30`. `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`. Pinned references: - https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/messageProcessor.go#L30 - https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/batch/batch.go#L122 - https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/transactionResolver.go#L194 - https://github.com/klever-io/klever-go/blob/333f6ec910906e227705fc5767dc897d8fbfc862/data/retriever/resolvers/trieNodeResolver.go#L108 This 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`. ### PoC Reproduced with: ```bash go run auditpoc/request_batch_hash_amplification_poc.go go test github.com/klever-io/klever-go/auditpoc -run TestRequestBatchHashAmplification_DirectSendReachability -count=1 ``` Observed output: ```text request wire bytes: 442 fits direct-send limit (983040 bytes): true tx resolver lookups: 200000 trie resolver lookups: 200000 heap delta before first tx lookup: 17.47 MiB ok github.com/klever-io/klever-go/auditpoc ``` The 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. ### Impact A 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.

Source published

5 Jun 2026 15:27:42 UTC

Source modified

25 Jun 2026 23:11:07 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH

Klever-Go KVM: Hash-array amplification in P2P resolver request handling in github.com/klever-io/klever-go

Source published

25 Jun 2026 22:34:38 UTC

Source modified

25 Jun 2026 23:01:26 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.