bitcoinjs-lib: Undetected merkle node duplication
Affects bitcoinjs-libSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.3 Critical : upgrade to 5.2.1 as a priority.
Data as of 10 Nov 2026, 17:35 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 9.3 |
|---|
- Patch
- Available – fixed in 5.2.1, 6.1.8, 7.0.2
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:H/SA:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade bitcoinjs-lib to 5.2.1; bitcoinjs-lib to 6.1.8; bitcoinjs-lib to 7.0.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmbitcoinjs-lib | Affected
| Fixed in
|
| npmbitcoinjs-lib | Affected
| Fixed in
|
| npmbitcoinjs-lib | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Fixed versions 5.2.1, 6.1.8, and 7.0.2 of bitcoinjs-lib address this vulnerability by presumably implementing checks to detect duplicated transactions in the Merkle tree computation. Users should upgrade to these versions or later. Since patchAvailable is true and fixedVersions are known, upgrading to these versions is the recommended remediation. No other mitigation is indicated by the vendor advisory.
Description
bitcoinjs-lib versions prior to 5.2.1, 6.1.8, and 7.0.2 contain a vulnerability (CVE-2026-107846) where the fastMerkleRoot function does not detect duplicated transactions used to pad odd levels in the Merkle tree. This allows a forged block with a different transaction list but the same Merkle root and block ID to be accepted by the library's checkTxRoots function. Bitcoin Core mitigates this by detecting such mutations and rejecting the block, but bitcoinjs-lib lacks this check.
References
- github.com/bitcoinjs/bitcoinjs-lib/security/advisories/GHSA-8vv3-6qpc-gpw6 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-107846 (opens in a new tab)
- github.com/bitcoinjs/bitcoinjs-lib/commit/009f165edfbf925cad8964b2dce478d18dd19449 (opens in a new tab)
- github.com/bitcoinjs/bitcoinjs-lib/commit/b79c7714c0687473dc6e25c69fc5fc597302c7a0 (opens in a new tab)
- github.com/bitcoinjs/bitcoinjs-lib/commit/f3434d1e4bb5e0784fe769c4cd08a243576232a1 (opens in a new tab)
- github.com/bitcoinjs/bitcoinjs-lib (opens in a new tab)