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CVE-2026-107846

9.3 critical

Critical (9.3).

On this page
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.

Severity

CVSS 4.0

9.3 critical
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
CWE
CWE-354 Improper Validation of Integrity Check Value
Published
Record from
the NVD, synced

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Versions

From the CNA's record in the CVE List.

ProductAffected
bitcoinjs-lib>= 2.3.0, < 5.2.1
bitcoinjs-lib>= 6.0.0, < 6.1.8
bitcoinjs-lib>= 7.0.0-rc.0, < 7.0.2

Attack patterns (CAPEC)

  • CAPEC-75 Manipulating Writeable Configuration Files Likelihood: High · Severity: Very High
  • CAPEC-145 Checksum Spoofing Severity: Medium
  • CAPEC-463 Padding Oracle Crypto Attack Severity: High

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

Check your stackJSON