Klever-Go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Summary

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 1.7.18.

Timeline

1. Aug 7, 2026, 10:36 PM UTCCVE published
2. Aug 10, 2026, 1:35 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: yes · Technical impact: partial

3. Aug 10, 2026, 1:36 PM UTCRecord last updated

Affected versions

• klever-io klever-go

  From 1.7.14 · fixed in 1.7.18

• github.com/klever-io/klever-goGo

  From 1.7.14 · fixed in 1.7.18

References 2