# CVE-2026-47249: Klever-Go KVM: Hash-array amplification in P2P resolver request handling

> A remote peer can cause memory and CPU exhaustion in Klever-Go nodes by sending small compressed requests that expand into massive hash arrays.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-w342-mj6g-v9c4, GO-2026-5685

## What is CVE-2026-47249?

CVE-2026-47249 is a high-severity denial of service vulnerability in klever-io klever-go, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-47249?

3 open source packages ship an affected version, including github.com/klever-io/klever-go.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.18 |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.18 |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.18 |

## How do I fix CVE-2026-47249?

Upgrade github.com/klever-io/klever-go to 1.7.18 or later.

## Is CVE-2026-47249 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47249 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47249 and fix it if it is affected.

What it is: CVE-2026-47249 is a high-severity denial of service vulnerability in klever-io klever-go, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47249 exists.

Affected packages and fixed versions:
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.18
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.18
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.18

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47249/ (Markdown: https://insights.sbomify.com/CVE-2026-47249/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47249
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47249
- OSV: https://osv.dev/vulnerability/CVE-2026-47249

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47249/
Summaries are generated and may contain mistakes; the official description above is the record.