CVE-2026-20275 in IOS XR Software
Summary
by MITRE • 09/02/2026
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-2026-20275 are related to incorrect calculation issues that are grouped under the Common Weakness Enumeration (CWE) CWE-682.
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Analysis
by VulDB Data Team • 09/02/2026
Cisco IOS XR Software has been updated through a series of hardening releases designed to address multiple internally discovered vulnerabilities identified during comprehensive security reviews conducted by the Cisco engineering team. These updates focus on resolving critical logic errors that could potentially impact system stability and integrity, reflecting the organization's commitment to proactive vulnerability management and product quality assurance for its routing infrastructure platforms.
The specific flaw tracked under CVE-2026-20275 is categorized as an incorrect calculation issue, which aligns with Common Weakness Enumeration identifier CWE-682. This type of weakness typically involves errors in arithmetic operations or logical evaluations that can lead to unexpected behavior within the software execution flow. In network operating systems like IOS XR, such miscalculations may result in improper resource allocation, erroneous state transitions, or failure to enforce intended security boundaries correctly during packet processing or configuration management tasks.
From an operational perspective, vulnerabilities associated with CWE-682 can have varying degrees of impact depending on the specific context within which they occur. While not all calculation errors lead directly to remote code execution, they can contribute to denial-of-service conditions by causing processes to crash or enter infinite loops when handling malformed inputs or edge-case scenarios. Additionally, if these miscalculations affect access control logic or authentication routines, they could potentially be leveraged for privilege escalation attacks, allowing an attacker to bypass intended restrictions and gain unauthorized administrative access to the network device.
The MITRE ATT&CK framework does not assign a direct tactic to CWE-682 itself as it is a weakness rather than a specific attack technique; however, exploitation of such flaws often falls under techniques related to resource exhaustion or privilege escalation depending on how the miscalculation is triggered and utilized by an adversary. Defenders should monitor for anomalous system behavior indicative of logic errors, such as unexpected process restarts or degraded performance during high-load conditions that might suggest exploitation attempts targeting these calculation vulnerabilities.
To mitigate risks associated with CVE-2026-20275 and related issues, network administrators are strongly advised to apply the latest software hardening releases provided by Cisco for their IOS XR platforms. Regular patching ensures that known logic flaws are corrected before they can be exploited in production environments. Furthermore, implementing defense-in-depth strategies such as strict access control lists, limiting management plane exposure, and enabling comprehensive logging will help detect any potential exploitation attempts early and reduce the overall attack surface available to malicious actors targeting these infrastructure components.