CVE-2026-117601: spesmilo electrum · Improper Verification of Cryptographic Signature
Affects spesmilo electrumSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical : upgrade to 4.8.3 as a priority.
Data as of 27 Oct 2026, 13:57 UTC
- Patch
- Available – fixed in 4.8.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade electrum and spesmilo/electrum to 4.8.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| spesmiloelectrum | Affected
| Fixed in
|
GitHubspesmilo/electrumpkg:github/spesmilo/electrumOther threats | 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
Upgrade Electrum to version 4.8.3 or later, where the signature verification issue is fixed. No other mitigations are indicated by the vendor advisory.
Description
Electrum versions before 4.8.3 have a vulnerability where the software fails to verify signatures of wallet-owned inputs in unconfirmed mempool transactions. This flaw allows malicious servers to replace a user's just-broadcast transaction with a conflicting transaction that appears to have zero fees and pays an attacker address. Users can be tricked into performing Replace-By-Fee (RBF) fee-bumping on this invalid transaction, effectively losing funds to the attacker. The issue is fixed in Electrum version 4.8.3.
References
- github.com/spesmilo/electrum/security/advisories/GHSA-6jp4-8v48-cc5v (opens in a new tab)
- github.com/spesmilo/electrum/commit/90fe30822561e515a9d2d6e5a352cc07780999eb (opens in a new tab)
- vulncheck.com/advisories/electrum-before-4.8.3-missing-signature-verification-of-mempool-transactions (opens in a new tab)