{"id":"EUVD-2026-25054","enisaUuid":"2674c2d1-4068-33cb-9fd2-93941c4902c5","description":"nimiq-block contains block primitives to be used in Nimiq\u0027s 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.","datePublished":"Apr 22, 2026, 7:13:04 PM","dateUpdated":"Apr 23, 2026, 2:15:20 PM","baseScore":9.6,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","references":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff\nhttps://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823\nhttps://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0\n","aliases":"CVE-2026-33471\n","assigner":"GitHub_M","epss":0.22,"enisaIdProduct":[{"id":"fcc83dda-94bd-311b-be53-b5ae71e8baff","product":{"name":"nimiq-block","vendor":{"name":"nimiq"}},"product_version":"\u003c 1.3.0"}],"enisaIdVendor":[{"id":"beb859ac-3ee2-3980-a5d4-eb4bf5cd87f0","vendor":{"name":"nimiq"}}],"enisaIdVulnerability":[{"id":"2f16e0ee-b58d-304c-ba92-e743486d00f3","vulnerability":{"id":"CVE-2026-33471","description":"nimiq-block contains block primitives to be used in Nimiq\u0027s 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.","datePublished":"Apr 22, 2026, 7:13:04 PM","dateUpdated":"Apr 23, 2026, 2:15:20 PM","status":"PUBLISHED","baseScore":9.6,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","references":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff\nhttps://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823\nhttps://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0\n","enisa_id":"EUVD-2026-25054\n","assigner":"GitHub_M","epss":0.22,"dataProcessed":"Oct 29, 2026, 7:17:53 AM","vulnerabilityProduct":[{"id":"a2588468-705e-3176-94c5-7e67ebccdbfa","product":{"name":"nimiq-block","vendor":{"name":"nimiq"}},"product_version":"\u003c 1.3.0"}],"vulnerabilityVendor":[{"id":"b1ecaa04-da9b-3cd8-a6e2-2af239d2ac6f","vendor":{"name":"nimiq"}}]}},{"id":"b68e0344-6f8c-3782-aea1-52ba46136e16","vulnerability":{"id":"GHSA-6973-8887-87ff","description":"nimiq-block has skip block quorum bypass via out-of-range BitSet indices \u0026 u16 truncation","datePublished":"Apr 22, 2026, 7:13:47 PM","dateUpdated":"Apr 27, 2026, 4:22:04 PM","baseScore":0.0,"references":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-33471\nhttps://github.com/nimiq/core-rs-albatross/pull/3657\nhttps://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823\nhttps://github.com/nimiq/core-rs-albatross\nhttps://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0\n","enisa_id":"EUVD-2026-25054\n","aliases":"CVE-2026-33471\nGHSA-6973-8887-87ff\n","epss":0.0,"dataProcessed":"Oct 25, 2026, 1:55:10 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}