PT-2026-34555 · Nimiq · Nimiq-Transaction

Published 2026-04-22 · Updated 2026-04-22 · CVE-2026-34068

Mitre

CVSS v3.1

6.8

Medium

AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

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.

Fix

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-347

Related Identifiers

CVE-2026-34068

Affected Products

Nimiq-Transaction

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-34068 · Security Note
• https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0 · Note
• https://github.com/nimiq/core-rs-albatross/commit/e7f0ab7d2115e17d6e5548ddc60f10df1a5d645f · Note
• https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-pf4j-pf3w-95f9 · Note
• https://github.com/nimiq/core-rs-albatross/pull/3654 · Note