CVE-2026-34068
Description
nimiq-transaction provides the transaction primitive to be used in Nimiq's Rust implementation. Prior to version 1.3.0, the staking contract accepts UpdateValidator transactions that set new_voting_key=Some(...) while omitting new_proof_of_knowledge. this skips the proof-of-knowledge requirement that is needed to prevent BLS rogue-key attacks when public keys are aggregated. Because tendermint macro block justification verification aggregates validator voting keys and verifies a single aggregated BLS signature against that aggregate public key, a rogue-key voting key in the validator set can allow an attacker to forge a quorum-looking justification while only producing a single signature. While the impact is critical, the exploitability is low: The voting keys are fixed for the epoch, so the attacker would need to know the next epoch validator set (chosen through VRF), which is unlikely. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
nimiq-transactioncrates.io | <= 0.2.0 | — |
Affected products
1Patches
1e7f0ab7d2115Fix missing proof-of-knowledge validation on voting key update
1 file changed · +5 −4
primitives/transaction/src/account/staking_contract/structs.rs+5 −4 modified@@ -144,10 +144,11 @@ impl IncomingStakingTransactionData { } // Check proof of knowledge, if necessary. - if let (Some(new_voting_key), Some(new_proof_of_knowledge)) = - (new_voting_key, new_proof_of_knowledge) - { - verify_proof_of_knowledge(new_voting_key, new_proof_of_knowledge)?; + match (new_voting_key, new_proof_of_knowledge) { + (Some(key), Some(pok)) => verify_proof_of_knowledge(key, pok)?, + (Some(_), None) => return Err(TransactionError::InvalidData), + (None, Some(_)) => return Err(TransactionError::InvalidData), + (None, None) => {} // no key change, nothing to verify } // Check that the signature is correct.
Vulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
6- github.com/nimiq/core-rs-albatross/commit/e7f0ab7d2115e17d6e5548ddc60f10df1a5d645fnvdPatchWEB
- github.com/nimiq/core-rs-albatross/pull/3654nvdIssue TrackingPatchWEB
- github.com/nimiq/core-rs-albatross/security/advisories/GHSA-pf4j-pf3w-95f9nvdPatchVendor AdvisoryWEB
- github.com/advisories/GHSA-pf4j-pf3w-95f9ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-34068ghsaADVISORY
- github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0nvdRelease NotesWEB
News mentions
0No linked articles in our index yet.