Quick answers
- Is CVE-2026-40093 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40093 being exploited in the wild.
- How severe is CVE-2026-40093?
- Critical severity, with a CVSS score of 9.1, published 9 April 2026.
- Which products and versions are affected?
- nimiq-blockchain (crates.io) <= 1.3.0, SEMVER:introduced=0,last_affected=1.3.0.
- Is there a fix for CVE-2026-40093?
- 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.
- How is CVE-2026-40093 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-40093?
- Check whether you run nimiq-blockchain (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.
Technical details
The nimiq-blockchain library lacks a wall-clock upper bound check during block timestamp validation. While it ensures timestamps are greater than or equal to the parent block, it does not verify them against the current real-world time. A malicious validator can produce blocks with arbitrary future timestamps, which directly impacts reward calculations in 'blockchain/src/reward.rs' via 'Policy::supply_at()' and 'batch_delay()'. This allows for the inflation of the monetary supply beyond the protocol's defined emission schedule. The vulnerability is present in versions up to and including 1.3.0.
Affected products
- Nimiq nimiq-blockchain <= 1.3.0
Identifiers
- CVE-2026-40093
- GHSA-49xc-52mp-cc9j
Timeline
- 2026-04-09: disclosed
- 2026-04-10: advisory