CVE-2025-20241: Cisco Nexus 3000 and 9000 Series Switches IS-IS Protocol <TBD> Denial of Service Vulnerability
Cisco · Cisco NX-OS Software
Affected: Cisco NX-OS Software · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 20% of scored CVEs
DescriptionCVE.org
A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) feature of Cisco NX-OS Software for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the IS-IS process to unexpectedly restart, which could cause an affected device to reload. This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device. A successful exploit could allow the attacker to cause the unexpected restart of the IS-IS process, which could cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Cisco · Cisco NX-OS Software9.2(3); 7.0(3)I5(2); 6.0(2)A8(7a); 7.0(3)I4(5); 7.0(3)I4(6); 7.0(3)I4(3) and 121 more
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Weakness
- Compiler Optimization Removal or Modification of Security-critical Code · Input Validation and Logic
- Vendor
- Cisco
- Published
- August 2025
CoverageNo articles yet
No CyberSIXT article names CVE-2025-20241 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.