SB2026100902 - Remote code execution in Cisco NX-OS Software NX-API
Published: October 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Heap-based buffer overflow (CVE-ID: CVE-2026-76471)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 10 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H]
The vulnerability allows a remote attacker to execute arbitrary code with root privileges or cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow associated with insufficient input validation in the NX-API feature of Cisco NX-OS Software when processing data sent to the API. A remote attacker can send a crafted HTTP request to the NX-API to execute arbitrary code with root privileges or cause a denial of service.
On Nexus 3000 and 9000 Series Switches, exploitation requires the NX-API feature to be enabled; it is disabled by default. Nexus 9000 Series Switches are affected only in standalone NX-OS mode. On UCS 6300 Series Fabric Interconnects, exploitation requires valid low-privileged user credentials and occurs through the Cisco UCS Manager XML API, which is enabled by default.
Remediation
Install update from vendor's website.