CVE-2026-40093 — HIGH (8.1)

Vulnerability Description

nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. In 1.3.0 and earlier, 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.

CVSS Score

8.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Nimiq	Nimiq Proof-Of-Stake	< 1.3.0

Related Weaknesses (CWE)

CWE-1284

References

https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-49xc-52mp-ccBroken Link

FAQ

What is CVE-2026-40093?

CVE-2026-40093 is a vulnerability with a CVSS score of 8.1 (HIGH). nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. In 1.3.0 and earlier, block timestamp validation enforces that timestamp >= parent.timestamp for non-skip blocks and...

How severe is CVE-2026-40093?

CVE-2026-40093 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-40093?

Check the references section above for vendor advisories and patch information. Affected products include: Nimiq Nimiq Proof-Of-Stake.