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CVE PROGRAM SOURCE RECORD6.8 Medium

CVE-2026-20171

Cisco Nexus 3000 and 9000 Series Border Gateway Protocol Denial of Service Vulnerability

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Status
Published
Published
Updated
Assigning organization
cisco

Description

A vulnerability in the Border Gateway Protocol (BGP) enforce-first-as feature of Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, remote attacker to trigger BGP peer flaps, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect parsing of a transitive BGP attribute. An attacker could exploit this vulnerability by sending a crafted BGP update through an established BGP peer session. If the update propagates to an affected device, it could cause the device to drop the BGP session and flap with the BGP peer that is forwarding this update, resulting in a DoS condition.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Cisco Cisco NX-OS Software

Default version status: unknown

  • 10.2(1)affected
  • 10.2(1q)affected
  • 10.2(2)affected
  • 10.2(3)affected
  • 10.2(3t)affected
  • 10.2(2a)affected
  • 10.3(1)affected
  • 10.2(4)affected
  • 10.3(2)affected
  • 10.3(3)affected
  • 10.2(5)affected
  • 10.2(3v)affected
  • 10.4(1)affected
  • 10.3(99w)affected
  • 10.2(6)affected
  • 10.3(3w)affected
  • 10.3(99x)affected
  • 10.3(3o)affected
  • 10.3(4)affected
  • 10.3(3p)affected
  • 10.3(4a)affected
  • 10.4(2)affected
  • 10.3(3q)affected
  • 10.3(5)affected
  • 10.2(7)affected
  • 10.4(3)affected
  • 10.3(3x)affected
  • 10.3(4g)affected
  • 10.5(1)affected
  • 10.2(8)affected
  • 10.3(3r)affected
  • 10.3(6)affected
  • 10.4(4)affected
  • 10.3(4h)affected
  • 10.5(2)affected
  • 10.3(7)affected
  • 10.4(5)affected
  • 10.5(3)affected
  • 10.2(9)affected
  • 10.4(4g)affected
  • 10.6(1)affected
  • 10.5(3t)affected
  • 10.3(8)affected
  • 10.4(6)affected
  • 10.5(3s)affected
  • 10.5(3e)affected
  • 10.5(3o)affected
  • 10.6(1s)affected
  • 10.5(3p)affected

References