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CVE-2026-76486

CRITICAL(9.8)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Risk Signal Score25/100 — MITTEL
  • CVSS 9.8 — Kritisch

Erwähnungen (letzte 60 Tage)

Artikel

EPSS-Score

0.5%

Exploit-Wahrscheinlichkeit (30 Tage)

CVSS Score

9.8

Technische Schwere

Beschreibung

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.

Erkennung & Indikatoren

Ausnutzung

In den geprüften Quellen nicht genannt

Threat-Hunting-Queries

Detection for crafted packets targeting Cisco NX-OS devices with NGOAM enabled, specifically when Segment Routing over IPv6 (SRv6) or Network Virtualization (NV) Overlay is also enabled. This requires monitoring network traffic for anomalies or malformed packets on IP interfaces of affected devices. Specific packet structures for exploitation are not provided, making generic behavioral detection c

Sentinel/Defender KQL

// This query is a placeholder. Specific detection for crafted NGOAM/SRv6/NV Overlay packets requires deep packet inspection capabilities and knowledge of exploit patterns, which are not detailed in the advisory.
// Consider monitoring for unusual traffic patterns to Cisco Nexus devices on relevant IP interfaces.
// Example (conceptual, requires specific packet details):
// NetworkEvents
// | where DestinationIP in ("<Cisco_Nexus_IPs>")
// | where Protocol == "IP"
// | where Payload contains "<NGOAM_Exploit_Pattern>" // Placeholder for actual exploit signature
// | summarize count() by SourceIP, DestinationIP, DestinationPort, Protocol

Splunk SPL

# This query is a placeholder. Specific detection for crafted NGOAM/SRv6/NV Overlay packets requires deep packet inspection capabilities and knowledge of exploit patterns, which are not detailed in the advisory.
# Consider monitoring for unusual traffic patterns to Cisco Nexus devices on relevant IP interfaces.
# Example (conceptual, requires specific packet details):
# index=network sourcetype=cisco_netflow dest_ip IN ("<Cisco_Nexus_IPs>")
# | where _raw LIKE "*<NGOAM_Exploit_Pattern>*" # Placeholder for actual exploit signature
# | stats count by src_ip, dest_ip, dest_port, protocol

Sigma

title: Cisco NX-OS NGOAM RCE Attempt
id: 00000000-0000-0000-0000-000000000001 # Placeholder UUID
status: experimental
description: Detects potential exploitation attempts against Cisco NX-OS NGOAM vulnerability (CVE-2026-76486).
references:
  - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ngoam-rce-LWKQ4BU
logsource:
  category: network_traffic
  product: firewall # Or other network monitoring solution
detection:
  selection:
    # This is a conceptual placeholder. Actual detection requires specific packet characteristics.
    # For example, look for malformed IP packets targeting Cisco Nexus devices on specific ports/protocols
    # associated with NGOAM, SRv6, or NV Overlay.
    # Example (highly conceptual):
    # dest_ip: '<Cisco_Nexus_IPs>'
    # protocol: 'ip'
    # payload|contains: '<NGOAM_Exploit_Signature_Pattern>'
    # As specific patterns are not provided, this rule needs customization based on observed exploit traffic.
    # A more generic approach would be to look for unexpected traffic to these services.
    # For now, this rule serves as a template.
    TargetedIPs:
      DestinationIP: ['<Cisco_Nexus_IP_Range_or_List>'] # Replace with actual IPs of vulnerable devices
    # No specific payload patterns are provided in the advisory, making a concrete rule difficult.
    # This rule would need to be refined with actual exploit traffic characteristics.
  condition: TargetedIPs
level: high

Elastic ES|QL

// This query is a placeholder. Specific detection for crafted NGOAM/SRv6/NV Overlay packets requires deep packet inspection capabilities and knowledge of exploit patterns, which are not detailed in the advisory.
// Consider monitoring for unusual traffic patterns to Cisco Nexus devices on relevant IP interfaces.
// Example (conceptual, requires specific packet details):
// from network_traffic
// | where destination.ip in ("<Cisco_Nexus_IPs>")
// | where network.transport == "ip"
// | where message matches "*<NGOAM_Exploit_Pattern>*" // Placeholder for actual exploit signature
// | summarize count() by source.ip, destination.ip, destination.port, network.transport

SecBoard-generated · behavioral · requires customization — Von SecBoard erzeugt und nicht in einer Zielumgebung validiert. Vor dem Einsatz an die eigene Protokollierung anpassen.

Referenzen