CVE-2026-46539 nimiq-primitives: BlockInclusionProof interlink issue when hops are empty
Attackers can forge block inclusion proofs by exploiting a logic flaw that skips verification when hop lists are empty, affecting Nimiq core-rs-albatross users.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-46539?
CVE-2026-46539 is a medium-severity vulnerability in nimiq core-rs-albatross, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.4.0, 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. This issue has been patched in version 1.4.0.
Weakness: CWE-345
Which versions are affected by CVE-2026-46539?
2 open source packages ship an affected version, including nimiq-primitives.
| Package | Affected | Fixed in |
|---|---|---|
nimiq-primitives crates.io | All versions to 0.2.0 | None |
nimiq-primitives crates.io | All versions to 0.2.0 | None |
How do I fix CVE-2026-46539?
No fix has been published for CVE-2026-46539 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-46539 being exploited?
There is no known exploitation of CVE-2026-46539 in the wild and no public exploit code.
Sources
Also known as GHSA-799f-29jm-gr6c.