Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M
CVE-2026-86065Klever-Go: Unauthenticated WebSocket /subscribe: no read-size limit, no connection cap, permissive origin -> remote node memory/goroutine exhaustion (DoS)
High 7.5
In plain English
A high-severity resource allocation without limits in klever-go from klever-io. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the default-open GET /subscribe endpoint in network/api/websocket/routes.go accepts unauthenticated WebSocket clients with permissive origin handling, does not call SetReadLimit to bound message size, and has no live-connection cap. SocketHub.HandleClientInsertion also accepts an unbounded address list that grows addressSubscription, and client.loopIn continues reading without a size limit, allowing one client to grow subscription maps or many clients to retain goroutines, buffered channels, and descriptors. The global HTTP request throttler does not count upgraded live WebSocket connections. Because the REST and WebSocket API runs in the node process, memory or scheduler exhaustion can crash the node and interrupt P2P and consensus participation. This issue is fixed in version 1.7.20.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/klever-io/klever-go | 1.7.20 | GHSA-4fwh-wrm6-97xm |
| Go | github.com/klever-io/klever-go | 1.7.20 | GO-2026-6581 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm x_refsource_CONFIRM
- https://github.com/klever-io/klever-go/pull/76 x_refsource_MISC
- https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2 x_refsource_MISC
- https://github.com/klever-io/klever-go/releases/tag/v1.7.20 x_refsource_MISC