CVE-2026-20277 HIGH

CVE-2026-20277: Cisco IOS XR Software Security Hardening Release: September 2026

Vendor Cisco
Product Cisco IOS XR Software
Weakness CWE-693
Published September 2, 2026
Last update September 2, 2026
View on NVD All CVEs

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

What the vulnerability does

01Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20277 are related to protection mechanism failure issues that are grouped under the Common Weakness Enumeration (CWE) CWE-693.

Key dates

02Disclosure timeline

September 2, 2026 CVE published
September 2, 2026 Record updated