CVE-2026-9258

Vulnerability

Canon EOS Network Setting Tool version 1.5.0 and earlier, included in EOS Utility versions 3.12.0 through 3.20.20, improperly validates SSH host keys during FTP, FTPS, and SFTP communication test functions [1]. This flaw allows an attacker to impersonate a legitimate server without detection.

Exploitation

An attacker with network access (e.g., man-in-the-middle position) can present a fake SSH server to the tool. Because the tool does not verify the host key, it will connect to the attacker-controlled server and transmit the authentication credentials (username and password) used in the communication test [1]. No user interaction beyond initiating the test is required.

Impact

Successful exploitation enables the attacker to capture FTP/FTPS/SFTP credentials, leading to unauthorized access to the target server and potential data exposure or further compromise [1].

Mitigation

Canon released EOS Utility version 3.20.21 on June 15, 2026, which includes an updated EOS Network Setting Tool that properly validates SSH host keys [1]. Users should update to this version or later. No workaround is available for earlier versions.