Cisco IOS XR Control Flow Management Vulnerability (CWE-691) CVE-2026-20276
CVE-2026-20276 Published on September 2, 2026

Cisco IOS XR Software Security Hardening Release: September 2026
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-2026-20276 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-691.

NVD

Vulnerability Analysis

CVE-2026-20276 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Insufficient Control Flow Management

The code does not sufficiently manage its control flow during execution, creating conditions in which the control flow can be modified in unexpected ways.


Products Associated with CVE-2026-20276

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Affected Versions

Cisco IOS XR Software: