CVE-2020-3527: Cisco IOS XE

High severity, CVSS 8.6. EPSS: 1.4% chance of exploitation in the next 30 days.

A vulnerability in the Polaris kernel of Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to crash the device. The vulnerability is due to insufficient packet size validation. An attacker could exploit this vulnerability by sending jumbo frames or frames larger than the configured MTU size to the management interface of this device. A successful exploit could allow the attacker to crash the device fully before an automatic recovery.

Affected products

• Cisco IOS XE: from 16.9.0, before 16.9.5 (fixed in 16.9.5); from 16.12.0, before 16.12.3 (fixed in 16.12.3)

Published 2020-09-24. Last modified 2026-06-17.