CVE-2026-76486: cisco cisco nx-os software Stack-based Buffer Overflow

Vulnerability summary

CVE-2026-76486 is a critical (CVSS 9.8) Stack-based Buffer Overflow vulnerability in cisco cisco nx-os software. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.5% of scored vulnerabilities.

Timeline

1. 07-10-2026
   PublishedVulnerability first disclosed.
2. 08-10-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability in the VXLAN Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software, known as NGOAM, could allow an unauthenticated, remote attacker to execute arbitrary code with root privileges or cause a Denial-of-Service (DoS) on an affected device. This vulnerability is due to improper input validation of IP traffic when the NGOAM feature is enabled. An attacker could exploit this vulnerability by sending crafted packets to an IP interface on an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges and could cause process crashes resulting in a reload and DoS condition.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).