CVE-2026-34063
network-libp2p: Peer can crash the node by opening discovery protocol substream twice
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
network-libp2p: Peer can crash the node by opening discovery protocol substream twice
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.
- Record
CVE-2026-34063- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
EUVDEUVD-2026-25058
7.5
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.
- Record
EUVD-2026-25058- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-34063- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
OSV
7.5
network-libp2p: Peer can crash the node by opening discovery protocol substream twice
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.
- Record
CVE-2026-34063- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-34063 is a high vulnerability (CVSS 7.5) in Nimiq Network-libp2p, published April 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 29th percentile. No source names a fixed version.
References
github.com/nimiq/core-rs-albatross/security/advisories/GHSA-74hp-mhfx-m45h
github.com/nimiq/core-rs-albatross/pull/3666
github.com/nimiq/core-rs-albatross/commit/e0d4e01994f061bf41d3c2835bc74040d3c084f5
github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0
github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34063.json
nvd.nist.gov/vuln/detail/CVE-2026-34063