CVE-2026-48486: Signum Node: Integer overflow in SMART_FEES fee distribution allows arbitrary miner reward inflation
Signum Node is a HDD-mined cryptocurrency using an energy efficient and fair Proof-of-Commitment (PoC+) consensus algorithm. Prior to version 3.9.9, an integer overflow in BlockServiceImpl.applyBlock() allowed a miner to receive an arbitrarily inflated block reward by crafting a block with a negative totalFeeCashBackNqt value. The vulnerability was introduced when the SMARTFEES hardfork (block ~1,029,000) enabled fee cash-back and burn accounting without overflow protection. This issue has been patched in version 3.9.9.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Signum Nodeto a version that resolves this vulnerability.Fixed in 3.9.9
Event History
Frequently Asked Questions
Which deployments are affected?
Signum Node versions prior to 3.9.9 are affected. The issue was introduced with the SMART_FEES hardfork, around block 1,029,000, when fee cash-back and burn accounting became enabled.
What does an attacker need to do to exploit this issue?
An attacker needs to craft a block with a negative totalFeeCashBackNqt value. Exploitation can cause the miner of that block to receive an arbitrarily inflated block reward.
Is authentication or user interaction required?
No privileges or user interaction are required according to the supplied CVSS vector. Exploitation is network-based, although the attack complexity is rated high.
What is the remediation?
Upgrade Signum Node to version 3.9.9, which patches the integer overflow in BlockServiceImpl.applyBlock().