{"id":"GHSA-6973-8887-87ff","revision":"e3db119cb74d4461aa42579a7ddc3feb","records":[{"revision":"e3db119cb74d4461aa42579a7ddc3feb","observedAt":"2026-10-30T17:47:16.231+00:00","statement":{"source":"osv","id":"GHSA-6973-8887-87ff","aliases":["CVE-2026-33471"],"title":"nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation","description":"### Impact\n`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. 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.\n\nThis 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.\n\n### Patches\n[The patch for this vulnerability](https://github.com/nimiq/core-rs-albatross/pull/3657) is included as part of [v1.3.0](https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0).\n\n### Workarounds\nNo known workarounds.","state":0,"publishedAt":"2026-04-22T19:13:47+00:00","modifiedAt":"2026-10-30T15:45:11.5360138+00:00","affected":[{"ecosystem":"crates.io","name":"nimiq-block","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"1.7.2"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"CRITICAL"}],"references":["https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff","https://nvd.nist.gov/vuln/detail/CVE-2026-33471","https://github.com/nimiq/core-rs-albatross/pull/3657","https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823","https://github.com/nimiq/core-rs-albatross","https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0"],"sourceUrl":"https://github.com/advisories/GHSA-6973-8887-87ff","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-6973-8887-87ff","identifiers":["GHSA-6973-8887-87ff","CVE-2026-33471"]},"retained":false,"historicalAffected":[]}],"coverage":[]}