A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing when parsing SNMP requests. An attacker could exploit this vulnerability by continuously sending SNMP queries to a specific MIB of an affected device. A successful exploit could allow the attacker to cause a kernel panic on the device, resulting in a reload and a DoS condition. Note: This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMPv1 or SNMPv2c, the attacker must have a valid read-only SNMP community string for the affected system. To exploit this vulnerability through SNMPv3, the attacker must have valid SNMP user credentials for the affected system.
The CVSS score for this vulnerability is 7.7, indicating a high severity level. The potential impact on organizations includes significant service disruption due to the denial of service condition. Given the nature of this vulnerability and its exploitation requirements, organizations utilizing affected devices should prioritize remediation efforts. As this vulnerability is classified as high severity, organizations should address it in priority patch cycles to mitigate risks effectively.
Currently, there are no known exploits or public proof of concept (PoC) available for this vulnerability. However, organizations should remain vigilant and proactive in monitoring for any emerging threats that could exploit this vulnerability.
In summary, organizations using Cisco Nexus 9000 Series Fabric Switches in ACI mode must prioritize addressing this high-severity vulnerability to ensure continued operational integrity and security.
Vulnerability Details
CVE-2026-20048 describes a vulnerability that affects the SNMP subsystem of Cisco Nexus 9000 Series Fabric Switches in ACI mode. It could allow an authenticated, remote attacker to cause a denial of service condition on an affected device due to improper SNMP request processing. The vulnerability has a CVSS score of 7.7, categorizing it as high severity. The affected systems include all versions of the Cisco Nexus 9000 Series Fabric Switches that utilize SNMP versions 1, 2c, and 3.
Technical Analysis
The root cause of this vulnerability is related to improper processing of SNMP requests within the affected SNMP subsystem. The attack vector is network-based, allowing remote exploitation without requiring physical access to the device. The attack complexity is low, and the attacker requires low privileges, specifically a valid read-only SNMP community string for SNMPv1 or SNMPv2c, or valid SNMP user credentials for SNMPv3. User interaction is not required.
Risk & Impact Analysis
The real-world risk associated with CVE-2026-20048 is significant, as successful exploitation could lead to a denial of service condition on affected devices, causing operational disruptions. Organizations utilizing Cisco Nexus 9000 Series Fabric Switches should be particularly cautious and prioritize remediation given the potential blast radius of this vulnerability. The urgency for addressing this vulnerability is high, and organizations should schedule remediation in their priority patch cycles to mitigate the risk effectively.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch of Cisco Nexus 9000 Series Fabric Switches in ACI mode are affected by this vulnerability.
Mitigation & Remediation
Organizations should prioritize patching immediately. Cisco has released patches to address this vulnerability. It is crucial to update all affected systems to the latest versions. For organizations that cannot apply patches immediately, consider implementing network controls to limit SNMP traffic to affected devices.Penetration testing can also help assess the effectiveness of applied mitigations.
Detection Guidance
Monitoring logs for unusual SNMP request patterns can help detect potential exploitation attempts. Additionally, organizations should look for signs of device reloads or kernel panics, which may indicate an ongoing attack.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-20048 lies in the increasing reliance on SNMP for network management. Organizations should take proactive measures to secure SNMP configurations as part of their overall cybersecurity strategy. Security teams should focus on understanding the implications of network vulnerabilities and consider adopting a vulnerability management program to enhance their defensive posture. Additionally, organizations should stay informed about emerging trends in network security, such as those highlighted in the 2026 ransomware targeting trends and adapt their defenses accordingly.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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