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8.6 High

CVE-2026-20084 A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to…

Description

A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause BOOTP packets to be forwarded between VLANs, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of BOOTP packets on Cisco Catalyst 9000 Series Switches. An attacker could exploit this vulnerability by sending BOOTP request packets to an affected device. A successful exploit could allow an attacker to forward BOOTP packets from one VLAN to another, resulting in BOOTP VLAN leakage and potentially leading to high CPU utilization. This makes the device unreachable (either through console or remote management) and unable to forward traffic, resulting in a DoS condition. Note: This vulnerability can be exploited with either unicast or broadcast BOOTP packets. There are workarounds that address this vulnerability.

Affected products and versions

Product Affected versions Fixed in
Cisco IOS XE Software 17.18.1 No fix stated
Cisco IOS XE Software 17.17.1 No fix stated
Cisco IOS XE Software 17.16.1 No fix stated
Cisco IOS XE Software 17.15 17.15.1 → 17.15.4 No fix stated
Cisco IOS XE Software 17.14.1 No fix stated
Cisco IOS XE Software 17.13.1 No fix stated
Cisco IOS XE Software 17.12 17.12.1z5 → 17.12.5 No fix stated
Cisco IOS XE Software 17.11.1 No fix stated
Cisco IOS XE Software 17.10 17.10.1b → 17.10.1 No fix stated
Show the 16 other branches
Product Affected versions Fixed in
Cisco IOS XE Software 17.9 17.9.1 → 17.9.8 No fix stated
Cisco IOS XE Software 17.8.1 No fix stated
Cisco IOS XE Software 17.7.1 No fix stated
Cisco IOS XE Software 17.6 17.6.1y → 17.6.8 No fix stated
Cisco IOS XE Software 17.5.1 No fix stated
Cisco IOS XE Software 17.4.1 No fix stated
Cisco IOS XE Software 17.3 17.3.1 → 17.3.8 No fix stated
Cisco IOS XE Software 17.2 17.2.1a → 17.2.1 No fix stated
Cisco IOS XE Software 17.1 17.1.1s → 17.1.3 No fix stated
Cisco IOS XE Software 16.12 16.12.1s → 16.12.8 No fix stated
Cisco IOS XE Software 16.11 16.11.1s → 16.11.1 No fix stated
Cisco IOS XE Software 16.10 16.10.1s → 16.10.1 No fix stated
Cisco IOS XE Software 16.9 16.9.1s → 16.9.8 No fix stated
Cisco IOS XE Software 16.8 16.8.1s → 16.8.1 No fix stated
Cisco IOS XE Software 16.7.1 No fix stated
Cisco IOS XE Software 16.6 16.6.1 → 16.6.10 No fix stated

References

Timeline

  1. Published
  2. Last modified

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