CVE-2026-34064 nimiq-account: Vesting insufficient funds error can panic

What is CVE-2026-34064?

CVE-2026-34064 is a medium-severity vulnerability in nimiq-account, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

nimiq-account contains account primitives to be used in Nimiq's Rust implementation. Prior to version 1.3.0, `VestingContract::can_change_balance` returns `AccountError::InsufficientFunds` when `new_balance < min_cap`, but it constructs the error using `balance: self.balance - min_cap`. `Coin::sub` panics on underflow, so if an attacker can reach a state where `min_cap > balance`, the node crashes while trying to return an error. The `min_cap > balance` precondition is attacker-reachable because the vesting contract creation data (32-byte format) allows encoding `total_amount` without validating `total_amount <= transaction.value` (the real contract balance). After creating such a vesting contract, the attacker can broadcast an outgoing transaction to trigger the panic during mempool admission and block processing. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.

Weakness: CWE-191

Which versions are affected by CVE-2026-34064?

2 open source packages ship an affected version, including nimiq-account. It affects 1 product.

Products include Nimiq Nimiq Proof-of-Stake.

How do I fix CVE-2026-34064?

No fix has been published for CVE-2026-34064 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-34064 being exploited?

There is no known exploitation of CVE-2026-34064 in the wild and no public exploit code.

Other vulnerabilities in nimiq-account

• CVE-2026-33471 nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation Critical 9.6
• CVE-2026-40093 nimiq-blockchain is missing a wall-clock upper bound on block timestamps High 8.1
• CVE-2026-34063 network-libp2p: Peer can crash the node by opening discovery protocol substream twice High 7.5
• CVE-2026-34065 nimiq-primitives: Node crash due to missing interlink validation in election macro block proposals High 7.5
• CVE-2026-32605 Nimiq: Remote crash via off-by-one signer bounds check in proposal buffer High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-vc34-39q2-m6q3.