A vulnerability in the Broadband Network Gateway PPP over Ethernet (PPPoE) feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the PPPoE process to continually crash. This vulnerability exists because the PPPoE feature does not properly handle an error condition within a specific crafted packet sequence. An attacker could exploit this vulnerability by sending a sequence of specific PPPoE packets from controlled customer premises equipment (CPE). A successful exploit could allow the attacker to cause the PPPoE process to continually restart, resulting in a denial of service condition (DoS).Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2022 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .