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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-47249: 0.49% estimated exploitation activity in the next 30 days; percentile 42.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A connected peer can send a compressed RequestDataTypeHashArrayType 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: -…

Published by the source

5 Jun 2026, 15:27 UTC

Last modified by the source

5 Jun 2026, 15:27 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-w342-mj6g-v9c4

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# Patch Next advisory brief: CVE-2026-47249

Advisory: Klever-Go KVM: Hash-array amplification in P2P resolver request handling
IDs: CVE-2026-47249, GHSA-w342-mj6g-v9c4
Record: https://patchnext.com/advisories/cve-2026-47249 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/klever-io/klever-go 1.7.18. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/klever-io/klever-go: affected < 1.7.18; fixed in 1.7.18

## Suggested inspection (read-only)
- Go github.com/klever-io/klever-go: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/klever-io/klever-go.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-w342-mj6g-v9c4 (GitHub-reviewed advisory GHSA-w342-mj6g-v9c4 lists affected ranges: Go github.com/klever-io/klever-go >=0 <1.7.18)

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