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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-47249?
3 open source packages ship an affected version, including github.com/klever-io/klever-go.
| Package | 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.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-47249 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47249 exists.
Sources
Also known as GHSA-w342-mj6g-v9c4, GO-2026-5685.