CRITICAL: CVE-2026-33471 (CVSS 9.6) — nimiq nimiq proof-of-stake

CVE: CVE-2026-33471

CVSS: 9.6 (3.1) — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

nimiq nimiq proof-of-stake

Summary

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.

Verified Sources

References

https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823
https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0
https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._

Lyrie Verdict

A vulnerability of this severity is exactly what Lyrie's anti-rogue-AI defense is built for: continuous, autonomous monitoring that doesn't wait for human reaction time.

#nimiq #critical