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

CVE-2026-34064 · Severity: medium · CVSS 5.3 · Published 2026-04-22

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.

Technologies: Nimiq Proof-Of-Stake. Vendors: crates.io, Nimiq.

Quick answers

Is CVE-2026-34064 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34064 being exploited in the wild.
How severe is CVE-2026-34064?
Medium severity, with a CVSS score of 5.3, published 22 April 2026.
Which products and versions are affected?
nimiq-account (crates.io) <= 0.2.0, SEMVER:introduced=0,last_affected=0.2.0.
Is there a fix for CVE-2026-34064?
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-2026-34064?
Check whether you run nimiq-account (crates.io) or Nimiq Proof-Of-Stake 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.

Affected products

  • nimiq-account (crates.io) <= 0.2.0, SEMVER:introduced=0,last_affected=0.2.0
  • Nimiq Proof-Of-Stake

Identifiers

  • CVE-2026-34064
  • GHSA-vc34-39q2-m6q3

References

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