{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:nimiq:nimiq_proof-of-stake:*:*:*:*:*:rust:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.3.0"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5bd15d9af710abeecdfb63d0a721dc883efb59c4"
            },
            {
              "fixed": "d02059053181ed8ddad6b59a0adfd661ef5cd823"
            }
          ],
          "repo": "https://github.com/nimiq/core-rs-albatross",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-6973-8887-87ff"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-1284",
      "CWE-190",
      "CWE-20",
      "CWE-345"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33471.json"
  },
  "details": "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.",
  "id": "CVE-2026-33471",
  "modified": "2026-07-08T05:37:22.483818587Z",
  "published": "2026-04-22T19:13:04.687Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33471.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33471"
    },
    {
      "type": "FIX",
      "url": "https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nimiq-block has skip block quorum bypass via out-of-range BitSet indices \u0026 u16 truncation"
}