Vulnerability in Cisco iOS Xr Software

CVE-2026-20276

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20276 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-691.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20276?
CVE-2026-20276 is a high-severity vulnerability in Cisco iOS Xr Software, classified under CWE-691. CVSS score: 8.6/10. Published 2026-09-02.
How severe is CVE-2026-20276?
High severity. CVSS v3 base score is 8.6 out of 10.