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Vesting insufficient funds error can panic

Moderate
jsdanielh published GHSA-vc34-39q2-m6q3 Apr 22, 2026

Package

cargo nimiq-account (Rust)

Affected versions

<=v1.2.2

Patched versions

v1.3.0

Description

Impact

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.

Patches

The patch for this vulnerability is formally released as part of v1.3.0.

Workarounds

No known workarounds.

References

See PR.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVE ID

CVE-2026-34064

Weaknesses

Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. Learn more on MITRE.

Credits