Buffer overflow in Cisco Nx-Os Software
CVE-2026-76459
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76459 are related to out-of-bounds write issues that are grouped under the Common Weakness Enumeration (CWE) CWE-787.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Cisco Nx-Os Software — versions 10.3(1), 10.3(2), 10.3(3)
- Cisco Nx-Os System Software In Aci Mode — versions 15.2(1g), 15.2(2e), 15.2(2f)
- Cisco Unified Computing System (Managed) — versions 4.0(1a), 4.0(1b), 4.0(1c)
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-76459?
- CVE-2026-76459 is a high-severity vulnerability in Cisco Nx-Os Software, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-10-07.
- How severe is CVE-2026-76459?
- High severity. CVSS v3 base score is 8.8 out of 10.