Cisco Warns of Critical Flaws in IOS XR Operating System

Cisco Systems has issued an alert to its customers regarding three critical-rated security vulnerabilities in its products, including two in the Cisco IOS XR operating system.

The first two flaws, CVE-2026-20274 and CVE-2026-20279, are rated 9.8 on the CVSS scale, indicating a high risk of exploitation.

Cisco discovered these vulnerabilities after conducting an internal security review, which may have involved using bug-finding models such as Mythos.

The company has released new versions of IOS XR to fix these issues and recommends that customers upgrade their systems as soon as possible.