CVE-2026-46539
nimiq-primitives: BlockInclusionProof interlink issue when hops are empty
Description
### Impact A logic flaw in `BlockInclusionProof::is_block_proven` causes the function to return true without performing any cryptographic verification when `get_interlink_hops` yields an empty hop list. This occurs when the target block is at the election block position immediately preceding the election head's epoch. An attacker providing transaction inclusion proofs can forge a MacroBlock header for that epoch position and have it accepted as "proven" without any hash or signature verification. ### Patches [The patch for this vulnerability](https://github.com/nimiq/core-rs-albatross/pull/3705) is formally released as part of [v1.4.0](https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0). ### Workarounds No Workarounds ### Resources See [PR](https://github.com/nimiq/core-rs-albatross/pull/3705).
How to fix CVE-2026-46539
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-2026-46539 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, <= 0.2.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |