CVE-2026-40094 nimiq-blockchain: network-libp2p untrusted peer can crash address book via empty peer contact addresses
An untrusted peer can crash the Nimiq blockchain node by submitting a peer contact with an empty address list, causing a panic during address book generation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-40094?
CVE-2026-40094 is a medium-severity denial of service vulnerability in nimiq core-rs-albatross, published on 20 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. In versions 1.3.0 and prior, network-libp2p discovery accepts signed PeerContact updates from untrusted peers and stores them in a peer contact book, eventually leading to address book crash. A PeerContact can legally contain an empty addresses list (no intrinsic validation enforces non-empty). Later, PeerContactBook::known_peers builds an address book by taking addresses.first().expect("every peer should have at least one address"). If the attacker has inserted a signed peer contact with addresses=[], any call to get_address_book (RPC/web client) can panic and crash the node/RPC task depending on panic settings. This issue has been fixed in version 1.4.0.
Weakness: CWE-754
Which versions are affected by CVE-2026-40094?
How do I fix CVE-2026-40094?
No fix has been published for CVE-2026-40094 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-40094 being exploited?
There is no known exploitation of CVE-2026-40094 in the wild and no public exploit code.
Sources
Also known as GHSA-c45m-6x25-3cjq.