CVE-2026-40093
nimiq-blockchain is missing a wall-clock upper bound on block timestamps
Description
### Impact Block timestamp validation enforces that `timestamp >= parent.timestamp` for non-skip blocks and `timestamp == parent.timestamp + MIN_PRODUCER_TIMEOUT` for skip blocks, but there is no visible upper bound check against the wall clock. A malicious block-producing validator can set block timestamps arbitrarily far in the future. This directly affects reward calculations via `Policy::supply_at()` and `batch_delay()` in `blockchain/src/reward.rs`, inflating the monetary supply beyond the intended emission schedule. ### Patches TBD ### Workarounds No know workarounds.
How to fix CVE-2026-40093
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- —no fix listed
Is CVE-2026-40093 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, <= 1.3.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |