CVE-2019-12665: Cisco IOS

High severity, CVSS 7.4. EPSS: 1.1% chance of exploitation in the next 30 days.

A vulnerability in the HTTP client feature of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to read and modify data that should normally have been sent via an encrypted channel. The vulnerability is due to TCP port information not being considered when matching new requests to existing, persistent HTTP connections. An attacker could exploit this vulnerability by acting as a man-in-the-middle and then reading and/or modifying data that should normally have been sent through an encrypted channel.

Affected products

• Cisco IOS: version 15.6(2)t only; version fd-1.5.0 only

Published 2019-09-25. Last modified 2026-06-17.