CVE-2026-117601 Electrum before 4.8.3 Missing Signature Verification of Mempool Transactions
Critical 9.3
Published
Updated
Check this codebase for CVE-2026-117601 and fix it if it is affected.
What it is: CVE-2026-117601 is a critical vulnerability in spesmilo electrum, published on 27 Oct 2026.
Exploitation: There is no known exploitation of CVE-2026-117601 in the wild and no public exploit code.
Affected packages and fixed versions:
- electrum (PyPI): affected all versions; fixed in 4.8.3
- electrum (PyPI): affected all versions; fixed in 4.8.3
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-117601/ (Markdown: https://insights.sbomify.com/CVE-2026-117601/index.md)
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-117601?
CVE-2026-117601 is a critical vulnerability in spesmilo electrum, published on 27 Oct 2026.
Official 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.
Weakness: CWE-347
Which versions are affected by CVE-2026-117601?
2 open source packages ship an affected version, including electrum.
| Package | Affected | Fixed in |
|---|---|---|
electrum PyPI | All versions | 4.8.3 |
electrum PyPI | All versions | 4.8.3 |
How do I fix CVE-2026-117601?
Upgrade electrum to 4.8.3 or later.
Is CVE-2026-117601 being exploited?
There is no known exploitation of CVE-2026-117601 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-117601, GHSA-6jp4-8v48-cc5v.