Is CVE-2026-86065 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-86065 being exploited in the wild.

How severe is CVE-2026-86065?

High severity, with a CVSS score of 7.5, published 23 September 2026.

Which products and versions are affected?

github.com/klever-io/klever-go (Go) < 1.7.20, SEMVER:introduced=0,fixed=1.7.20.

Is there a fix for CVE-2026-86065?

Yes. github.com/klever-io/klever-go (Go): upgrade to 1.7.20 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-86065 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-86065?

Check whether you run github.com/klever-io/klever-go (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-86065: Klever-Go unauthenticated WebSocket /subscribe remote DoS

Q: Is there a fix for CVE-2026-86065?

Yes. github.com/klever-io/klever-go (Go): upgrade to 1.7.20 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-86065 attacked?

It is attacked over the network, in a hosted service.

Q: Am I affected by CVE-2026-86065?

Check whether you run github.com/klever-io/klever-go (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-86065 · Severity: high · CVSS 7.5 · Published 2026-09-23

Klever-Go's WebSocket subscription endpoint allows unauthenticated remote attackers to exhaust a node's memory and goroutines, crashing the entire node including its P2P and consensus functions. An attacker can send a single oversized message or open many connections to force resource exhaustion; the endpoint is exposed by default and accepts cross-origin requests, making it reachable even from browser-based attacks. No authentication, account, stake, or funds are required.

Technologies: github.com/klever-io/klever-go (Go). Vendors: Go.

Quick answers

Is CVE-2026-86065 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-86065 being exploited in the wild.
How severe is CVE-2026-86065?: High severity, with a CVSS score of 7.5, published 23 September 2026.
Which products and versions are affected?: github.com/klever-io/klever-go (Go) < 1.7.20, SEMVER:introduced=0,fixed=1.7.20.
Is there a fix for CVE-2026-86065?: Yes. github.com/klever-io/klever-go (Go): upgrade to 1.7.20 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-86065 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-86065?: Check whether you run github.com/klever-io/klever-go (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/klever-io/klever-go (Go): upgrade to 1.7.20 or later
```
go get github.com/klever-io/klever-go@v1.7.20
```

Technical details

The unauthenticated GET /subscribe WebSocket endpoint (network/api/websocket/routes.go) contains three compounding remote code execution gaps: (1) CheckOrigin always returns true, permitting cross-origin WebSocket upgrades; (2) no conn.SetReadLimit() is enforced, allowing a single WebSocket frame to trigger unbounded heap allocation in gorilla's JSON parsing; (3) no per-connection, per-IP, or global cap on live WebSocket connections, and req.Addresses is uncapped, causing both goroutine exhaustion and hub-map memory growth. The REST API runs in-process with the node, so crashing the API kills P2P and consensus participation. Attack vectors include network-reachable APIs and cross-origin browser drive-by attacks against localhost-bound nodes. Three independent PoCs confirm all gaps in production code at commit 23b74e1.

Affected products

Klever Klever-Go up to commit 23b74e1

Identifiers

CVE-2026-86065
GHSA-4fwh-wrm6-97xm
GO-2026-6581

Timeline

2026-09-23: disclosed: GitHub advisory GHSA-4fwh-wrm6-97xm published

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