Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| spesmilo | electrum | < 4.8.3 | 4.8.3 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | electrum | 4.8.3+dfsg-1 | — |
| Debian 13 | electrum | No fix yet | — |
| Debian 12 | electrum | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | electrum | < 4.8.3 | 4.8.3 | GHSA-6jp4-8v48-cc5v |
References
- GitHub Security Advisory (GHSA-6jp4-8v48-cc5v) vendor-advisory
- Patch Commit patch
- VulnCheck Advisory: Electrum before 4.8.3 Missing Signature Verification of Mempool Transactions third-party-advisory