CVEvulnerability

CVE-2026-20074

7.4 HIGH Published 2026-03-11 Modified 2026-07-08 Official page ↗
Status
Analyzed
Published
2026-03-11
Last modified
2026-07-08
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.4 HIGH — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weaknesses
CWE-1287

Description

A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) multi-instance routing feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the IS-IS process to restart unexpectedly. This vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.  

Affected configurations

• cisco ios xr (>= 7.8.0 < 25.2.2) • cisco ios xr 25.3.0

Related

Weakness · CWE (1)

  • CWE-1287 Improper Validation of Specified Type of Input weakness

References