CRITICAL 9.3 NVD
CVE-2026-117601
Electrum before 4.8.3 fails to verify signatures of wallet-owned inputs in unconfirmed mempool transactions, allowing malicious servers to replace a just-broadc
Electrum before 4.8.3 fails to verify signatures of wallet-owned inputs in unconfirmed mempool transactions, allowing malicious servers to replace a just-broadcast transaction with a conflicting one. Attackers can swallow the user's transaction and display an invalid zero-fee copy paying an attacker address, tricking users into RBF fee-bumping and signing it.
References
- https://github.com/spesmilo/electrum/commit/90fe30822561e515a9d2d6e5a352cc07780999eb
- https://github.com/spesmilo/electrum/security/advisories/GHSA-6jp4-8v48-cc5v
- https://www.vulncheck.com/advisories/electrum-before-4.8.3-missing-signature-verification-
This critical severity vulnerability with a CVSS score of 9.3 was published on 2026-10-27 via NVD.
Risk Timeline
CVE Disclosed2026-10-27 · -1 days ago
Remediation Resources
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