The pip package openssl-encrypt (versions 1.4.8 and earlier) stores mTLS client private keys in cleartext within a world-readable SharedPreferences file (permissions 0644). This exposure occurs via the desktop GUI Settings screen when a combined certificate and private key PEM is entered. A local attacker with filesystem access can trivially read the private key, enabling potential impersonation or decryption of mTLS-protected communications. The vulnerability is classified as a sensitive data exposure / insecure storage issue. Version 1.4.9 addresses this by writing the PEM to a dedicated file with restricted permissions (0600), storing only the file path in SharedPreferences, and migrating or scrubbing any existing cleartext values. The fix represents a significant improvement in credential storage hygiene. The issue is tracked as CVE-2026-81683 and has been disclosed via GitHub Security Advisories and VulnCheck.