Vulnerability in Cisco iOS Xe Software

CVE-2026-20270

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20270 are related to incorrect calculation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-682.

EPSS: 0.003 (21.1th percentile) — read the EPSS interpretation.

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-2026-20270?
CVE-2026-20270 is a high-severity vulnerability in Cisco iOS Xe Software, classified under Incorrect Calculation. CVSS score: 8.6/10. Published 2026-08-05.
How severe is CVE-2026-20270?
High severity. CVSS v3 base score is 8.6 out of 10.