CVE-2026-59776 FeliCa IC chips vulnerability

Who is affected

How to fix it

CVE-2026-59776 affects FeliCa IC chips and involves cryptographic validation failure. An attacker with the required local access may reuse or forge trusted policy data and weaken enforcement. Prioritize internet-facing, privileged, automation, and production deployments. Follow Sony's FeliCa advisory to identify affected chips shipped in or before 2017, replace or reissue affected cards or devices where required, and move sensitive use cases to supported hardware.

1. Inventory every deployment, device, package, plugin, container, build, and environment that uses FeliCa IC chips.
2. Compare the installed version with the recorded affected range: shipped in or before 2017.
3. Follow Sony's FeliCa advisory to identify affected chips shipped in or before 2017, replace or reissue affected cards or devices where required, and move sensitive use cases to supported hardware.
4. Until remediation is complete, remove public management access, isolate affected devices, and allow administration only from a trusted network.
5. Review configuration, roles, tokens, network paths, and exposed endpoints connected to FeliCa IC chips; remove access that is not required.
6. Review application, system, proxy, and audit logs for requests and behavior linked to the affected feature and CVE.
7. If exploitation is suspected, isolate affected assets, preserve evidence, rotate exposed credentials or keys, restore trusted data, and rebuild compromised systems before returning them to service.

Verify the fix

• Confirm every affected asset now runs the fixed vendor-supported release or has the documented mitigation for CVE-2026-59776 in place.
• Use a safe regression test to confirm the affected cryptographic validation failure path no longer produces the vulnerable behavior.
• Confirm temporary access controls, endpoint restrictions, network blocks, and least-privilege settings remain effective after the update.
• Review post-remediation logs and rerun Fixnx plus the relevant package, dependency, firmware, browser, or product-specific security check.
• Document affected assets, versions, changes, validation evidence, reviewed logs, and any credential rotation, cleanup, or replacement completed.

Related categories

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