CVE-2026-20276
Received Received - Intake

Insufficient Control Flow Management in Cisco IOS XR Software

Publication date: 2026-09-02

Last updated on: 2026-09-02

Assigner: Cisco Systems, Inc.

Description
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.

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Meta Information

Published
2026-09-02
Last Modified
2026-09-02
Generated
2026-09-02
AI Q&A
2026-09-02
EPSS Evaluated
N/A
NVD
CVE-2026-20276
EUVD
EUVD-2026-70203

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
cisco ios_xr_software *
cisco ios_xr_software 26.2.2
cisco ios_xr_software 26.3.1
cisco ios_xr_software From 26.2.2 (inc) to 26.3.1 (inc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-691 The code does not sufficiently manage its control flow during execution, creating conditions in which the control flow can be modified in unexpected ways.

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Executive Summary

CVE-2026-20276 is a vulnerability in Cisco IOS XR Software caused by insufficient control flow management, specifically related to CWE-691. It includes issues like reachable assertions and loops with unreachable exit conditions, which can lead to system instability or crashes.

Impact Analysis

This vulnerability could cause affected systems to crash or become unresponsive due to control flow issues. Since it affects all Cisco IOS XR Software releases, it may disrupt network operations, leading to downtime or service interruptions if not patched.

Mitigation Strategies

Upgrade to fixed software releases such as 26.2.2 or 26.3.1. No workarounds are available, so applying the software update is the only mitigation.

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