CVE-2026-9259: Canon EOS Network Setting Tool Improper Server Certificate Validation

Overview

CVE-2026-9259 describes improper validation of server certificates in the Canon EOS Network Setting Tool, version 1.5.0 or earlier. The weakness is classified as CWE-295 (Improper Certificate Validation). When a client does not properly verify the certificate presented by a server, it may be unable to tell a legitimate endpoint from an impostor, which weakens the confidentiality and integrity of the communication.

Impact

The NVD vector describes a network-reachable issue that requires no privileges and no user interaction, with high impact on confidentiality, integrity and availability. The NVD base score is 9.8. Canon's own product-level scores in the record are 6.5 and 7.1, so the severity depends on which scoring source is used. Organizations should weigh the vector and the scoring context specific to their deployment.

Affected products and versions

• Canon Inc. EOS Network Setting Tool: versions before 1.5.1.
• Canon Inc. EOS Network Setting Tool for macOS: version 1.5.0 or earlier.
• Canon Inc. EOS Network Setting Tool for Windows: version 1.5.0 or earlier.

The record does not include a fixed-version field. The affected range suggests that 1.5.1 is the first release outside the vulnerable range, but the vendor advisories should be checked to confirm this.

Exploitation status

The CISA Known Exploited Vulnerabilities catalog does not list this CVE, and the record does not report active exploitation. The SSVC data in the record indicates no known exploitation and that the issue is automatable. The EPSS probability in the record is 0.00345, which is low. No confirmed exploitation appears in the sources consulted.

Remediation and mitigation

• Identify all installations of the tool on Windows and macOS systems and record their versions.
• Update installations to a version later than 1.5.0, and confirm the release that the vendor marks as fixed, which the record suggests is 1.5.1.
• Review the vendor advisories from Canon for official remediation steps and any workarounds.
• Until the update is applied, limit use of the tool to trusted networks and avoid using it to connect to untrusted servers.

Detection guidance

• Maintain an inventory that includes the tool and its version on endpoints used for camera network configuration.
• Review software asset records for installations of the affected versions.
• Monitor for unexpected network connections from the tool to hosts that are not part of the expected configuration environment.

Limitations of the available information

The record contains the NVD and CVE Program descriptions, scores, the CWE classification and four vendor advisory links. The advisory contents were not available in the record, so details of the vulnerable code path, the exact fixed build and the vendor's own mitigation guidance are unknown. The record also contains inconsistent scoring between providers, which should be considered when prioritizing remediation.

Frequently asked questions

What is CVE-2026-9259?

It is an improper validation of server certificates in the Canon EOS Network Setting Tool, version 1.5.0 or earlier, classified as CWE-295.

Which versions are affected?

The record lists versions before 1.5.1 for the base product, and version 1.5.0 or earlier for the macOS and Windows variants.

Is this CVE known to be exploited?

It is not listed in the CISA KEV catalog and the record does not report active exploitation. No confirmed exploitation appears in the sources consulted.

What should administrators do?

Inventory installed copies of the tool, update to a release later than 1.5.0 as confirmed by the vendor advisories, and restrict use to trusted networks until the update is applied.

This analysis was drafted with AI assistance from verified source data and automatically checked against it.