Arbitrary miner reward inflation via unchecked fee subtraction
Published Sep 3, 2026 · Updated Sep 3, 2026
Integer overflow in Signum Network Signum Node before 3.9.9 allows remote attackers to inflate miner rewards with a crafted block. The BlockServiceImpl.applyBlock() method subtracts an attacker-controlled negative totalFeeCashBackNqt using unchecked long arithmetic, wrapping the fee reward to a large positive value. A miner must forge a consensus-valid block after SMART_FEES activation; accepting nodes credit the inflated reward, corrupt ledger state, and can split the chain.
Summary
What happened
Integer overflow in Signum Network Signum Node before 3.9.9 allows remote attackers to inflate miner rewards with a crafted block. The BlockServiceImpl.applyBlock() method subtracts an attacker-controlled negative totalFeeCashBackNqt using unchecked long arithmetic, wrapping the fee reward to a large positive value. A miner must forge a consensus-valid block after SMART_FEES activation; accepting nodes credit the inflated reward, corrupt ledger state, and can split the chain.
The record
- CVE
- CVE-2026-48486
- Published
- Sep 3, 2026
- Updated
- Sep 3, 2026
- Vendor
- Signum Network
- Product
- Signum Node
- Classifications
- CWE-190, T1565.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 3, 2026CVE publishedPublication date reported by the CVE source.
- Sep 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.9.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Reported exploitation
- Mainnet exploitation at block 1,541,011reported exploitation
Technologies
Your stack
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Your stack
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