CVE-2026-107846— bitcoinjs-lib: Undetected merkle node duplication in block root computation validates a forged transaction list

Quick assessment

Affected

bitcoinjs bitcoinjs-lib

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

bitcoinjs-lib 是一个用于 Node.js 和浏览器的 JavaScript 比特币库。在版本 2.3.0 至 5.2.1、6.1.8 和 7.0.2 之间，fastMerkleRoot 函数在填充奇数层默克尔树时，会将最后一个节点与其自身进行哈希运算，但并未报告由此产生的相邻重复哈希值。受影响的区块根验证功能最初以 Block.checkMerkleRoot() 的形式随 Block.calculateMerkleRoot() 一同引入；而在后续版本中，验证逻辑通过 checkTxRoots() 和

CVSS 9.3 · Critical EPSS 0.18% · P8 Updated Nov 05, 2026

Possible ATT&CK Techniques 2 AI

T1083 · File and Directory Discovery T1190 · Exploit Public-Facing Application

Affected Version Matrix 3

Vendor	Product	Version Range	Status
bitcoinjs	bitcoinjs-lib	`>= 2.3.0, < 5.2.1`	affected
		`>= 6.0.0, < 6.1.8`	affected
		`>= 7.0.0-rc.0, < 7.0.2`	affected

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Vulnerability Information

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Vulnerability Title

bitcoinjs-lib: Undetected merkle node duplication in block root computation validates a forged transaction list

Source: CVE Program / CVE List V5

Vulnerability 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.

Source: CVE Program / CVE List V5

CVSS Information

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

Source: CVE Program / CVE List V5

Vulnerability Type

完整性检查值验证不恰当

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
bitcoinjs	bitcoinjs-lib	>= 2.3.0, < 5.2.1	-

II. Public POCs for CVE-2026-107846

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-107846

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Other References for CVE-2026-107846 (4)

https://github.com/bitcoinjs/bitcoinjs-lib/security/advisories/GHSA-8vv3-6qpc-gpw6 x_refsource_CONFIRM
https://github.com/bitcoinjs/bitcoinjs-lib/commit/f3434d1e4bb5e0784fe769c4cd08a243576232a1 x_refsource_MISC
https://github.com/bitcoinjs/bitcoinjs-lib/commit/b79c7714c0687473dc6e25c69fc5fc597302c7a0 x_refsource_MISC
https://github.com/bitcoinjs/bitcoinjs-lib/commit/009f165edfbf925cad8964b2dce478d18dd19449 x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-107846

IV. Related Vulnerabilities

Same vendor: bitcoinjs

Same weakness: CWE-354