๐Ÿ” CVE Alert

CVE-2026-86065

HIGH 7.5

Klever-Go: Unauthenticated WebSocket /subscribe: no read-size limit, no connection cap, permissive origin -> remote node memory/goroutine exhaustion (DoS)

CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-770
Vendor klever-io
Product klever-go
Published Sep 23, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

klever-io / klever-go
< 1.7.20

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm github.com: https://github.com/klever-io/klever-go/pull/76 github.com: https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2 github.com: https://github.com/klever-io/klever-go/releases/tag/v1.7.20