{"id":"CVE-2026-33471","revision":"8f591ffb09714727bd1473965a3b6a2f","records":[{"revision":"8f591ffb09714727bd1473965a3b6a2f","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-33471","aliases":[],"title":"nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation","description":"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.","state":0,"publishedAt":"2026-04-22T19:13:04.687+00:00","modifiedAt":"2026-04-23T14:15:20.57+00:00","affected":[{"ecosystem":"Vendor product","name":"nimiq-block","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"nimiq\",\n                    \"product\": \"nimiq-block\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 1.3.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","score":9.6,"severity":"CRITICAL"}],"references":["https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff","https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823","https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-33471","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-33471","identifiers":["CVE-2026-33471"]},"retained":false,"historicalAffected":[]}],"coverage":[]}