CVE-2026-20040 – Cisco IOS XR – Privilege Escalation and RCE
“When core routing software is exposed, attackers don’t just get access—they get control of the network itself.”
Cisco addressed multiple high-impact vulnerabilities in IOS XR that could allow attackers to escalate privileges and execute arbitrary code on affected devices. These flaws impact core routing infrastructure, creating risk to availability, integrity, and control of network traffic.
CVE-2026-20040 has a CVSS score of 8.8, which is High severity. CVE-2026-20046 has a CVSS score of 8.8, which is High severity. These vulnerabilities can be exploited over the network and could enable attackers to gain elevated privileges or execute code, depending on the attack path and exposure of the affected services.
The patch strengthens input validation, hardens privilege boundaries, and eliminates the conditions that allow unauthorized code execution and escalation. There is no confirmed real-world exploitation at this time, but given the critical role of IOS XR in service provider and enterprise networks, the potential impact is severe.
Key Details
- Attack Vector
- Local
- Attack Complexity
- Low
- Privileges Required
- Low
- User Interaction
- None
- CWE Classification
- CWE-78