Buffer overflow in Cisco iOS Xe Software
CVE-2026-20268
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-2026-20268 are related to issues with improper restriction of operations within the bounds of a memory buffer that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-119.
Vulnerability class: Buffer Overflow
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
- Cisco Ios Xe Software — versions 17.2.1a, 16.12.1y, 16.12.3s
- Cisco Ios_xe — versions 16.6.2, 16.6.3, 16.6.4
Weakness classification (CWE)
References
- psirt@cisco.com (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-20268?
- CVE-2026-20268 is a high-severity vulnerability in Cisco iOS Xe Software, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.6/10. Published 2026-08-05.
- How severe is CVE-2026-20268?
- High severity. CVSS v3 base score is 8.6 out of 10.