{"affected":[{"product":"bitcoinjs-lib","source":"CNA: GitHub_M","vendor":"bitcoinjs","versions":[{"status":"affected","version":">= 2.3.0, < 5.2.1"},{"status":"affected","version":">= 6.0.0, < 6.1.8"},{"status":"affected","version":">= 7.0.0-rc.0, < 7.0.2"}]}],"cveId":"CVE-2026-107846","cwes":["CWE-354"],"description":"bitcoinjs-lib is a JavaScript Bitcoin library for Node.js and browsers. From 2.3.0 until 5.2.1, 6.1.8, and 7.0.2, fastMerkleRoot pads odd Merkle-tree levels by hashing the final node with itself but does not report adjacent duplicate hashes. The affected block-root verifier was introduced as Block.checkMerkleRoot() alongside Block.calculateMerkleRoot(), while later versions expose validation through checkTxRoots() and __checkMerkleRoot; these validation paths can accept a recomputed root without checking for mutation. A peer can append duplicate transactions so a different transaction list retains the original Merkle root, block header, proof of work, and block identifier. Consumers that rely on block-root validation, including explorers, exchange indexers, or SPV clients, can process a duplicated transaction twice or blacklist the shared block hash and reject the honest block. This issue is fixed in versions 5.2.1, 6.1.8, and 7.0.2.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":9.3,"severity":"critical","source":"CNA: GitHub_M","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:H/SA:H","version":"4.0"}],"modifiedAt":1793818959453,"publishedAt":1793818959453,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/bitcoinjs/bitcoinjs-lib/security/advisories/GHSA-8vv3-6qpc-gpw6"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/bitcoinjs/bitcoinjs-lib/commit/009f165edfbf925cad8964b2dce478d18dd19449"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/bitcoinjs/bitcoinjs-lib/commit/b79c7714c0687473dc6e25c69fc5fc597302c7a0"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/bitcoinjs/bitcoinjs-lib/commit/f3434d1e4bb5e0784fe769c4cd08a243576232a1"}],"remediation":[],"revision":"b3a9ff9d1df2524bc55863f32e2f321b0aaae9ffe3cae5a8246eae73c13ca78d","sources":[{"modifiedAt":1793818959453,"name":"CNA: GitHub_M","retrievedAt":1793822901981,"url":"https://www.cve.org/CVERecord?id=CVE-2026-107846"}],"ssvc":null,"status":"published","title":"bitcoinjs-lib: Undetected merkle node duplication in block root computation validates a forged transaction list","updatedAt":1793822901981}