CVE-2026-86065
Klever-Go: Unauthenticated WebSocket /subscribe: no read-size limit, no connection cap, permissive origin -> remote node memory/goroutine exhaustion (DoS)
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.
INFO
Published Date :
Sept. 23, 2026, 8:17 p.m.
Last Modified :
Sept. 23, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-86065
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Klever-Go to version 1.7.20.
- Apply available patches for older versions.
- Review WebSocket origin handling.
- Implement message size limits.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-86065.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-86065 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-86065
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-86065 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-86065 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 23, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-770 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/86xxx/CVE-2026-86065.json">CVE-2026-86065</a> Added Reference https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2 Added Reference https://github.com/klever-io/klever-go/pull/76 Added Reference https://github.com/klever-io/klever-go/releases/tag/v1.7.20 Added Reference https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm