PT-2026-34542 · Nimiq · Core-Rs-Albatross+1

Published 2026-04-22 · Updated 2026-04-22 · CVE-2026-33471

Mitre

CVSS v3.1

9.6

Critical

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

nimiq-block contains block primitives to be used in Nimiq's Rust implementation. SkipBlockProof::verify computes its quorum check using BitSet.len(), then iterates BitSet indices and casts each usize index to u16 (slot as u16) for slot lookup. Prior to version 1.3.0, if an attacker can get a SkipBlockProof verified where MultiSignature.signers contains out-of-range indices spaced by 65536, these indices inflate len() but collide onto the same in-range u16 slot during aggregation. This makes it possible for a malicious validator with far fewer than 2f+1 real signer slots to pass skip block proof verification by multiplying a single BLS signature by the same factor. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.

Fix

Insufficient Verification of Data Authenticity

RCE

Integer Overflow

Weakness Enumeration

CWE-345

CWE-1284

CWE-20

CWE-190

Related Identifiers

CVE-2026-33471

Affected Products

Core-Rs-Albatross

Nimiq-Block

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-33471 · Security Note
• https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0 · Note
• https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff · Note
• https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823 · Note