# CVE-2026-34063: Nimiq's network-libp2p is a Nimiq network implementation based on libp2p. Prior to version 1.3.0, `network-libp2p`…

Source: https://junglewise.ai/threats/cve-2026-34063-nimiq-s-network-libp2p-is-a-nimiq-network-implementation-based-on  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-22  
License: CC BY 4.0 with a link back

CVE-2026-34063 · Severity: high · CVSS 7.5 · Published 2026-04-22

Nimiq's network-libp2p is a Nimiq network implementation based on libp2p. Prior to version 1.3.0, `network-libp2p` discovery uses a libp2p `ConnectionHandler` state machine. the handler assumes there is at most one inbound and one outbound discovery substream per connection. if a remote peer opens/negotiate the discovery protocol substream a second time on the same connection, the handler hits a `panic!(\"Inbound already connected\")` / `panic!(\"Outbound already connected\")` path instead of failing closed. This causes a remote crash of the networking task (swarm), taking the node's p2p networking offline until restart. The patch for this vulnerability is formally released as part of v1.3.0. No known workarounds are available.

Technologies: [Nimiq Proof-Of-Stake](https://junglewise.ai/threats/technologies/nimiq-proof-of-stake). Vendors: [Nimiq](https://junglewise.ai/threats/vendors/nimiq).

## Quick answers

**Is CVE-2026-34063 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34063 being exploited in the wild.

**How severe is CVE-2026-34063?** High severity, with a CVSS score of 7.5, published 22 April 2026.

**Which products and versions are affected?** Nimiq Proof-Of-Stake. The advisory does not name versions.

**Is there a fix for CVE-2026-34063?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-34063?** Check whether you run Nimiq Proof-Of-Stake. 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.

## Affected products

- Nimiq Proof-Of-Stake

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