CVE-1999-0159: Cisco IOS

Low severity, CVSS 3.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.

Affected products

• Cisco IOS: version 9.1 only; version 11.0(20.3) only; version 11.1(15)ca only; version 11.1(16) only; version 11.1(16)aa only; version 11.1(16)ia only; …

Published 1998-08-12. Last modified 2026-06-16.