Threat Notice: Cisco NX-OS Nexus 3000 and 9000 Series Switches. Cisco disclosed five critical vulnerabilities in NX-OS, the operating system powering Nexus 3000 and 9000 Series data center switches last week. Making sure this gets seen more broadly. Action: apply the NX-OS updates. References: Cisco Advisory: CVE-2026-76471 (NX-API): https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-napi-rce-r2shwu2j . Cisco Advisory: CVE-2026-76485, CVE-2026-76486, CVE-2026-76501 (NGOAM): https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ngoam-rce-LWKQ4BU. Cisco Advisory: CVE-2026-76465 (MPLS OAM): https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-moam-rce-uBTzYV7

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-2026-76458 are related to improper handling of exceptional conditions issues that are grouped under the Common Weakness Enumeration (CWE) CWE-703.

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.

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-2026-76457 are related to out-of-bounds read issues that are grouped under the Common Weakness Enumeration (CWE) CWE-125.

A vulnerability in the Switch Integrated Security Features (SISF) of Cisco IOS Software, Cisco IOS XE Software, Cisco NX-OS Software, and Cisco Wireless LAN Controller (WLC) AireOS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to the incorrect handling of DHCPv6 packets. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Cisco released its semiannual Cisco FXOS and NX-OS Software Security Advisory Bundled Publication on February 26, 2025. In direct response to customer feedback, Cisco releases bundles of Cisco FXOS and NX-OS Software Security Advisories on the fourth Wednesday of the month in February and August of each calendar year.The February 26, 2025, release of the Cisco FXOS and NX-OS Software Security Advisory Bundled Publication includes two Cisco Security Advisories that describe two vulnerabilities in Cisco NX-OS Software. Cisco has released software updates that address these vulnerabilities.

A vulnerability in the bootloader of Cisco NX-OS Software could allow an unauthenticated attacker with physical access to an affected device, or an authenticated, local attacker with administrative credentials, to bypass NX-OS image signature verification.  This vulnerability is due to insecure bootloader settings. An attacker could exploit this vulnerability by executing a series of bootloader commands. A successful exploit could allow the attacker to bypass NX-OS image signature verification and load unverified software.

A vulnerability in the bootloader of Cisco NX-OS Software could allow an unauthenticated attacker with physical access to an affected device, or an authenticated, local attacker with administrative credentials, to bypass NX-OS image signature verification. This vulnerability is due to insecure bootloader settings. An attacker could exploit this vulnerability by executing a series of bootloader commands. A successful exploit could allow the attacker to bypass NX-OS image signature verification and load unverified software.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-image-sig-bypas-pQDRQvjL

A vulnerability in the Python interpreter of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to escape the Python sandbox and gain unauthorized access to the underlying operating system of the device. The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by manipulating specific functions within the Python interpreter. A successful exploit could allow an attacker to escape the Python sandbox and execute arbitrary commands on the underlying operating system with the privileges of the authenticated user.  Note: An attacker must be authenticated with Python execution privileges to exploit these vulnerabilities. For more information regarding Python execution privileges, see product-specific documentation, such as the section of the Cisco Nexus 9000 Series NX-OS Programmability Guide.

A vulnerability in the Python interpreter of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to escape the Python sandbox and gain unauthorized access to the underlying operating system of the device. The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by manipulating specific functions within the Python interpreter. A successful exploit could allow an attacker to escape the Python sandbox and execute arbitrary commands on the underlying operating system with the privileges of the authenticated user.  Note: An attacker must be authenticated with Python execution privileges to exploit these vulnerabilities. For more information regarding Python execution privileges, see product-specific documentation, such as the section of the Cisco Nexus 9000 Series NX-OS Programmability Guide.

A vulnerability in the Python interpreter of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to escape the Python sandbox and gain unauthorized access to the underlying operating system of the device. The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by manipulating specific functions within the Python interpreter. A successful exploit could allow an attacker to escape the Python sandbox and execute arbitrary commands on the underlying operating system with the privileges of the authenticated user.  Note: An attacker must be authenticated with Python execution privileges to exploit these vulnerabilities. For more information regarding Python execution privileges, see product-specific documentation, such as the section of the Cisco Nexus 9000 Series NX-OS Programmability Guide.

A vulnerability in the DHCPv6 relay agent of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific fields in a DHCPv6 RELAY-REPLY message. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to any IPv6 address that is configured on an affected device. A successful exploit could allow the attacker to cause the dhcpsnoop process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to execute arbitrary commands on the underlying operating system of an affected device.  This vulnerability is due to insufficient validation of arguments for a specific CLI command. An attacker could exploit this vulnerability by including crafted input as the argument of the affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of the currently logged-in user.

A vulnerability in Cisco NX-OS Software could allow an authenticated, local attacker with privileges to access the Bash shell to execute arbitrary code as root on an affected device. This vulnerability is due to insufficient security restrictions when executing commands from the Bash shell. An attacker with privileges to access the Bash shell could exploit this vulnerability by executing a specific crafted command on the underlying operating system. A successful exploit could allow the attacker to execute arbitrary code with the privileges of root.

A vulnerability in Cisco NX-OS Software could allow an authenticated, local attacker with privileges to access the Bash shell to elevate privileges to network-admin on an affected device. This vulnerability is due to insufficient security restrictions when executing application arguments from the Bash shell. An attacker with privileges to access the Bash shell could exploit this vulnerability by executing crafted commands on the underlying operating system. A successful exploit could allow the attacker to create new users with the privileges of network-admin.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to execute arbitrary commands on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of arguments for a specific

Multiple vulnerabilities in the Python interpreter of Cisco NX-OS Software could allow an authenticated, low-privileged, local attacker to escape the Python sandbox and gain unauthorized access to the underlying operating system of the device.These vulnerabilities are due to

A vulnerability in the DHCPv6 relay agent of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.This vulnerability is due to improper handling of specific fields in a DHCPv6 RELAY-REPLY message. An

Multiple vulnerabilities in Cisco NX-OS Software could allow an authenticated, local attacker with privileges to access the Bash shell to execute arbitrary code with root privileges or elevate privileges to network-admin on an affected device.For more information about

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated user in possession of Administrator credentials to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of arguments that are passed to specific configuration CLI commands. An attacker could exploit this vulnerability by including crafted input as the argument of an affected configuration CLI command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of root. Note: To successfully exploit this vulnerability on a Cisco NX-OS device, an attacker must have Administrator credentials. The following Cisco devices already allow administrative users to access the underlying operating system through the bash-shell feature, so, for these devices, this vulnerability does not grant any additional privileges: Nexus 3000 Series Switches Nexus 7000 Series Switches that are running Cisco NX-OS Software releases 8.1(1) and later Nexus 9000 Series Switches in standalone NX-OS mode

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated user in possession of Administrator credentials to execute arbitrary commands as root on the underlying operating system of an affected device.This vulnerability is due to insufficient

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific fields in an LLDP frame. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface of an affected device and having an authenticated user retrieve LLDP statistics from the affected device through CLI show commands or Simple Network Management Protocol (SNMP) requests. A successful exploit could allow the attacker to cause the LLDP service to crash and stop running on the affected device. In certain situations, the LLDP crash may result in a reload of the affected device. Note: LLDP is a Layer 2 link protocol. To exploit this vulnerability, an attacker would need to be directly connected to an interface of an affected device, either physically or logically (for example, through a Layer 2 Tunnel configured to transport the LLDP protocol).

A vulnerability in the access control list (ACL) programming for port channel subinterfaces of Cisco Nexus 3000 and 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, remote attacker to send traffic that should be blocked through an affected device. This vulnerability is due to incorrect hardware programming that occurs when configuration changes are made to port channel member ports. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to access network resources that should be protected by an ACL that was applied on port channel subinterfaces.

A vulnerability with the handling of MPLS traffic for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the netstack process to unexpectedly restart, which could cause the device to stop processing network traffic or to reload. This vulnerability is due to lack of proper error checking when processing an ingress MPLS frame. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that is encapsulated within an MPLS frame to an MPLS-enabled interface of the targeted device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition. Note: The IPv6 packet can be generated multiple hops away from the targeted device and then encapsulated within MPLS. The DoS condition may occur when the NX-OS device processes the packet.

A vulnerability in the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because eBGP traffic is mapped to a shared hardware rate-limiter queue. An attacker could exploit this vulnerability by sending large amounts of network traffic with certain characteristics through an affected device. A successful exploit could allow the attacker to cause eBGP neighbor sessions to be dropped, leading to a DoS condition in the network.

A vulnerability in the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.This vulnerability exists because eBGP traffic is mapped to a shared

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.This vulnerability is due to improper handling of

A vulnerability with the handling of MPLS traffic for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the netstack process to unexpectedly restart, which could cause the device to stop processing network traffic or to reload. This vulnerability is