## Electrum: Malicious server can replace a just-broadcast tx and try to trick user into RBF-ing it

- 種別: advisory
- 重大度: critical
- 関連技術: python
- CVE: CVE-2026-117601
- 公開日時: 2026-10-28T21:23:44.000Z
- 情報源: GitHub Advisory Database (https://github.com/advisories/GHSA-6jp4-8v48-cc5v)
- パーマリンク: https://vulnpulse.app/items/ghsa-ghsa-6jp4-8v48-cc5v

影響: pip:electrum < 4.8.3 → 4.8.3
The main Electrum server the client connects to is trusted with mempool ("unconfirmed") transactions. This is documented [design](https://electrum.readthedocs.io/en/latest/faq.html#does-electrum-trust-servers). [0] However now someone figured out a way to practically exploit it: - when the client broadcasts a new tx1, a malicious server can swallow it, - and update the client's history with a conflicting (invalid) tx2 that replaces the outputs with the attacker's output address. - Tx2 has inval…