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.
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:
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.
Reproduced with:
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:
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.
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.
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.