CVE-2026-117602 in Electrum
Summary
by MITRE • 10/27/2026
Electrum 4.6.0 before 4.7.2 contains an authorization bypass in the external plugin loader, which executes a plugin's __init__.py module when the plugin is marked enabled in the config file, without verifying its plugin-password signature. A rogue local process with write access to the Electrum data directory can place plugin code in the plugins/ folder and mark it enabled, causing arbitrary code execution inside the Electrum process.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in Electrum versions prior to 4.7.2 represents a critical authorization bypass within the application's external plugin loading mechanism. This flaw stems from an insufficient verification of digital signatures for plugins that are explicitly marked as enabled in the configuration file. When the Electrum client initializes, it scans the designated plugins directory and loads any module whose _init_.py is flagged as active in the user's config settings. The security model assumes that enabling a plugin implies trust or prior validation; however, the implementation fails to cryptographically verify the integrity of these modules before execution. Consequently, if an attacker can write arbitrary code into this directory and manipulate the configuration file to enable it, they can bypass all intended security checks designed to prevent unauthorized script execution within the wallet environment.
From a technical perspective, the core issue lies in the logic flow of the plugin loader which prioritizes the state defined in the config file over cryptographic validation. The application reads the enabled status from the local configuration and proceeds directly to import and execute the _init_.py module associated with that plugin path. There is no intermediate step where the system checks a signature database or validates a hash against a known good baseline before running the code. This design decision creates a direct pathway for arbitrary code execution, as the application treats any file in the plugins directory marked as enabled as trusted software, regardless of its origin or content integrity.
The operational impact of this vulnerability is severe due to the high privileges typically held by wallet applications on local systems. A rogue process with write access to the Electrum data directory can exploit this flaw to achieve arbitrary code execution within the context of the user running Electrum. This could lead to the theft of private keys, manipulation of transaction details, or complete compromise of the host system if the user runs the application with elevated privileges. The attacker does not need network access or complex exploitation techniques; they only require local file write permissions and the ability to modify a configuration text file, which are relatively common attack vectors in scenarios involving malware infection or compromised user accounts.
This vulnerability aligns closely with CWE-287, Improper Authentication, as it involves failing to properly verify credentials or integrity before granting access to sensitive functionality. It also maps to MITRE ATT&CK technique T1059, Command and Scripting Interpreter, specifically through the abuse of legitimate system processes like Python scripts to execute malicious payloads. The attack vector is classified under Local Privilege Escalation or Code Injection depending on the initial foothold, but fundamentally it represents a failure in input validation regarding file integrity and trust boundaries within application extensions.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Users should immediately upgrade to Electrum version 4.7.2 or later, where this authorization bypass has been patched by enforcing signature verification for all enabled plugins regardless of their configuration status. In the interim, users can mitigate risk by restricting file write permissions on the Electrum data directory using operating system-level access control lists, ensuring that only trusted processes have modification rights to the plugins folder and config files. Additionally, enabling strict execution policies or sandboxing the wallet application can reduce the blast radius if a compromise occurs. Future development should implement a whitelist approach for plugin sources rather than relying solely on configuration flags, ensuring that every loaded module is cryptographically signed by a recognized authority before any code is executed.