{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-33471",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-03-20T16:16:48.969Z",
        "datePublished": "2026-04-22T19:13:04.687Z",
        "dateUpdated": "2026-04-23T14:15:20.570Z"
    },
    "containers": {
        "cna": {
            "title": "nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-20",
                            "lang": "en",
                            "description": "CWE-20: Improper Input Validation",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-190",
                            "lang": "en",
                            "description": "CWE-190: Integer Overflow or Wraparound",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-345",
                            "lang": "en",
                            "description": "CWE-345: Insufficient Verification of Data Authenticity",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1284",
                            "lang": "en",
                            "description": "CWE-1284: Improper Validation of Specified Quantity in Input",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 9.6,
                        "baseSeverity": "CRITICAL",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "LOW",
                        "scope": "CHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff"
                },
                {
                    "name": "https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823"
                },
                {
                    "name": "https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0"
                }
            ],
            "affected": [
                {
                    "vendor": "nimiq",
                    "product": "nimiq-block",
                    "versions": [
                        {
                            "version": "< 1.3.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-04-22T19:45:53.754Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "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."
                }
            ],
            "source": {
                "advisory": "GHSA-6973-8887-87ff",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-04-23T14:15:09.611330Z",
                                "id": "CVE-2026-33471",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-04-23T14:15:20.570Z"
                }
            }
        ]
    }
}