Threat Intelligence

Cisco Patches Critical Flaw Allowing Root Access on Nexus 9000 Switches

The Hacker News · 4 Sept 2026

Key Takeaway If your business relies on Cisco Nexus 9000 switches or IOS XR-based network equipment, apply the latest security patches immediately, as no workaround exists to protect against these critical flaws.

Cisco has issued patches for a critical security flaw affecting 10 of its Silicon One-based Nexus 9000 switch models. Tracked as CVE-2026-20212 and rated 9.8 out of 10 in severity, the vulnerability could allow an unauthenticated remote attacker to execute code with root-level privileges — the highest level of system access — without needing any login credentials.

Alongside this, Cisco released a hardening update for its IOS XR software bundling seven separate vulnerabilities (tracked under an umbrella advisory), two of which also carry the maximum-concern 9.8 severity rating. Notably, Cisco has confirmed there is no workaround available for any affected version of IOS XR, meaning organisations must apply the official patch to be protected — there is no interim mitigation to fall back on.

Network switches and routers running these systems are typically core infrastructure, often exposed to internal or even external networks, making them attractive targets. Successful exploitation could give attackers complete control over affected devices, potentially enabling data interception, network disruption, or use as a launchpad for further attacks. Given the severity scores and lack of workarounds, businesses using this equipment should treat these updates as urgent.

Summarised by CISO AI from The Hacker News. We link back to every original so you can read it yourself.