Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt

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-2026-52878: 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 Every transaction gossiped on the klever-go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback. The validator txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. A protobuf Transaction whose embedded RawData sub-message is omitted decodes to RawData == nil, so validating it triggers a nil-pointer panic. The libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and klever's own network/p2p layer install no recover(), so the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required. Aimed at enough of the BLS validator set, repeated delivery halts block production (chain halt). Affected component - Root cause: core/versioning/txVersionChecker.go:22 - Reached via: core/process/transaction/interceptedTransaction.go:203 (integrity) and :154 (CheckValidity) - Production…

Published by the source

5 Jun 2026, 16:42 UTC

Last modified by the source

9 Jun 2026, 18:40 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rm5c-5x2p-48wr

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-52878

Advisory: Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt
IDs: CVE-2026-52878, GHSA-rm5c-5x2p-48wr
Record: https://patchnext.com/advisories/cve-2026-52878 (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 >= 1.7.14, <= 1.7.17; 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-rm5c-5x2p-48wr (GitHub-reviewed advisory GHSA-rm5c-5x2p-48wr lists affected ranges: Go github.com/klever-io/klever-go >=1.7.14 <=1.7.17)

Commands are suggestions: review each one before running it.