CVE-2026-9261: Use of weak SSH cryptographic algorithms in Canon EOS Network Setting Tool Version 1

Synopsis

Use of weak SSH cryptographic algorithms affects Canon EOS Network Setting Tool version 1.5.0 and earlier on both Windows and macOS. The tool negotiates SSH connections using cryptographically weak algorithms, reachable over the network, with no authentication required from the attacker but requiring some form of user interaction to trigger. Successful exploitation allows an attacker to read and tamper with SSH session data, exposing confidential information and enabling modification of data in transit. No fix version has been published; HarborGuard tracks the advisory for patch availability.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must reach the target service over the network; the tool exposes an SSH endpoint that is accessible remotely.

• AuthenticationNot required

  No credentials or prior account access are needed to initiate the attack against the weak SSH negotiation.

• Victim interactionRequired

  A user must take some action, such as initiating or accepting an SSH connection, for the attacker to intercept or manipulate the session.

• Attack complexityDetail

  Exploitation requires specific environmental conditions, such as the ability to perform a man-in-the-middle position or influence algorithm negotiation, making reliable exploitation dependent on network positioning.

Blast Radius

• Reads confidential data transmitted over the SSH session, including credentials, commands, and any files transferred.
• Modifies data in transit over the SSH connection, allowing the attacker to inject or alter commands and file contents.
• Session confidentiality and integrity are fully compromised; an attacker with a successful interception position has high-fidelity access to the communication channel.