Cisco IOS XE Improper Neutralization of Special Elements (CWE-74)
CVE-2026-20272 Published on August 5, 2026
Cisco IOS XE Software Security Hardening Release
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-20272 are related to issues with improper neutralization of special elements that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-74.
Vulnerability Analysis
CVE-2026-20272 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 be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is an Injection Vulnerability?
The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Software has certain assumptions about what constitutes data and control respectively. It is the lack of verification of these assumptions for user-controlled input that leads to injection problems. Injection problems encompass a wide variety of issues -- all mitigated in very different ways and usually attempted in order to alter the control flow of the process. For this reason, the most effective way to discuss these weaknesses is to note the distinct features which classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed. The most classic instantiations of this category of weakness are SQL injection and format string vulnerabilities.
CVE-2026-20272 has been classified to as an Injection vulnerability or weakness.
Products Associated with CVE-2026-20272
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Affected Versions
Cisco IOS XE Software:- Version 17.2.1a is affected.
- Version 16.12.1y is affected.
- Version 16.12.3s is affected.
- Version 16.7.1b is affected.
- Version 16.6.2 is affected.
- Version 16.6.5 is affected.
- Version 16.12.1w is affected.
- Version 16.9.1d is affected.
- Version 17.3.1 is affected.
- Version 16.9.4c is affected.
- Version 16.7.1 is affected.
- Version 17.2.1 is affected.
- Version 16.6.8 is affected.
- Version 16.9.1b is affected.
- Version 16.9.2s is affected.
- Version 16.12.4 is affected.
- Version 16.12.3a is affected.
- Version 17.1.1s is affected.
- Version 16.11.1a is affected.
- Version 16.7.2 is affected.
- Version 16.11.1b is affected.
- Version 16.9.1s is affected.
- Version 16.9.3h is affected.
- Version 16.9.1c is affected.
- Version 16.6.5a is affected.
- Version 16.6.3 is affected.
- Version 16.10.1f is affected.
- Version 17.2.1v is affected.
- Version 16.8.1e is affected.
- Version 16.9.3a is affected.
- Version 16.12.1a is affected.
- Version 16.12.1x is affected.
- Version 16.6.4s is affected.
- Version 16.10.1c is affected.
- Version 16.12.3 is affected.
- Version 16.11.2 is affected.
- Version 16.6.5b is affected.
- Version 16.12.2s is affected.
- Version 16.10.1b is affected.
- Version 16.7.3 is affected.
- Version 16.6.7 is affected.
- Version 16.9.6 is affected.
- Version 16.9.2 is affected.
- Version 16.10.1 is affected.
- Version 16.12.1t is affected.
- Version 16.9.1 is affected.
- Version 16.8.1a is affected.
- Version 16.9.3s is affected.
- Version 16.6.7a is affected.
- Version 16.12.2 is affected.
- Version 16.11.1 is affected.
- Version 16.9.3 is affected.
- Version 16.11.1s is affected.
- Version 16.12.1 is affected.
- Version 17.1.1 is affected.
- Version 17.1.2 is affected.
- Version 16.10.1d is affected.
- Version 17.1.1t is affected.
- Version 16.9.4 is affected.
- Version 16.8.3 is affected.
- Version 16.12.2t is affected.
- Version 16.9.5 is affected.
- Version 16.8.1s is affected.
- Version 16.10.1e is affected.
- Version 16.8.2 is affected.
- Version 16.6.4 is affected.
- Version 16.8.1b is affected.
- Version 16.10.1a is affected.
- Version 16.12.1z is affected.
- Version 16.8.1c is affected.
- Version 16.9.1a is affected.
- Version 16.9.5f is affected.
- Version 16.6.4a is affected.
- Version 16.10.1g is affected.
- Version 16.8.1 is affected.
- Version 16.6.6 is affected.
- Version 16.9.2a is affected.
- Version 16.8.1d is affected.
- Version 16.10.3 is affected.
- Version 16.7.1a is affected.
- Version 16.11.1c is affected.
- Version 16.10.1s is affected.
- Version 17.2.1r is affected.
- Version 17.1.1a is affected.
- Version 16.10.2 is affected.
- Version 16.12.2a is affected.
- Version 16.12.1c is affected.
- Version 16.12.1s is affected.
- Version 16.7.4 is affected.
- Version 17.2.2 is affected.
- Version 16.9.8 is affected.
- Version 16.9.7 is affected.
- Version 17.1.3 is affected.
- Version 17.3.1a is affected.
- Version 17.3.2a is affected.
- Version 16.12.5 is affected.
- Version 17.3.1w is affected.
- Version 17.3.2 is affected.
- Version 17.4.1 is affected.
- Version 16.12.4a is affected.
- Version 17.4.1a is affected.
- Version 17.3.1x is affected.
- Version 17.3.3 is affected.
- Version 16.6.9 is affected.
- Version 17.2.3 is affected.
- Version 17.5.1 is affected.
- Version 16.12.1z1 is affected.
- Version 16.12.5a is affected.
- Version 17.4.1b is affected.
- Version 17.3.1z is affected.
- Version 16.12.5b is affected.
- Version 17.4.2 is affected.
- Version 17.3.3a is affected.
- Version 17.3.5 is affected.
- Version 17.3.4 is affected.
- Version 17.5.1a is affected.
- Version 16.12.6 is affected.
- Version 17.6.1 is affected.
- Version 16.12.1z2 is affected.
- Version 16.6.10 is affected.
- Version 17.3.4a is affected.
- Version 17.6.1a is affected.
- Version 17.7.1 is affected.
- Version 17.6.1x is affected.
- Version 17.6.2 is affected.
- Version 16.12.6a is affected.
- Version 17.3.4c is affected.
- Version 17.4.2a is affected.
- Version 17.3.4b is affected.
- Version 17.7.1a is affected.
- Version 16.12.7 is affected.
- Version 17.8.1a is affected.
- Version 17.6.3a is affected.
- Version 17.6.3 is affected.
- Version 17.7.2 is affected.
- Version 17.7.1b is affected.
- Version 17.9.1w is affected.
- Version 17.3.5a is affected.
- Version 17.6.1z is affected.
- Version 16.12.8 is affected.
- Version 17.8.1 is affected.
- Version 17.9.1 is affected.
- Version 17.6.4 is affected.
- Version 17.3.5b is affected.
- Version 17.9.1a is affected.
- Version 17.3.6 is affected.
- Version 17.10.1 is affected.
- Version 16.9.8a is affected.
- Version 17.6.1z1 is affected.
- Version 17.10.1a is affected.
- Version 17.9.2 is affected.
- Version 17.6.5 is affected.
- Version 17.9.1x is affected.
- Version 17.9.1y is affected.
- Version 16.9.8b is affected.
- Version 17.3.7 is affected.
- Version 17.9.2a is affected.
- Version 17.9.3 is affected.
- Version 16.12.9 is affected.
- Version 17.11.1 is affected.
- Version 17.10.1b is affected.
- Version 17.6.6 is affected.
- Version 17.9.1x1 is affected.
- Version 17.11.1a is affected.
- Version 17.9.3a is affected.
- Version 17.12.1 is affected.
- Version 17.3.8 is affected.
- Version 17.9.4 is affected.
- Version 16.12.10 is affected.
- Version 17.12.1w is affected.
- Version 17.9.1y1 is affected.
- Version 17.12.1a is affected.
- Version 17.9.5 is affected.
- Version 17.13.1 is affected.
- Version 17.12.1x is affected.
- Version 17.12.2 is affected.
- Version 17.14.1 is affected.
- Version 17.9.4a is affected.
- Version 17.3.8a is affected.
- Version 17.6.6a is affected.
- Version 17.6.5a is affected.
- Version 17.6.7 is affected.
- Version 16.12.10a is affected.
- Version 17.15.1 is affected.
- Version 17.13.1a is affected.
- Version 17.12.2a is affected.
- Version 16.12.11 is affected.
- Version 17.12.3 is affected.
- Version 17.12.1y is affected.
- Version 17.12.1z is affected.
- Version 17.9.5a is affected.
- Version 17.14.1a is affected.
- Version 17.9.5b is affected.
- Version 17.6.8 is affected.
- Version 16.12.12 is affected.
- Version 17.12.4 is affected.
- Version 17.9.6 is affected.
- Version 17.17.1 is affected.
- Version 17.16.1 is affected.
- Version 17.15.1w is affected.
- Version 17.12.3a is affected.
- Version 17.9.5c is affected.
- Version 17.15.1a is affected.
- Version 17.12.1z1 is affected.
- Version 17.15.2 is affected.
- Version 17.15.1b is affected.
- Version 17.9.5d is affected.
- Version 17.15.1x is affected.
- Version 17.9.6a is affected.
- Version 17.12.1z2 is affected.
- Version 17.6.8a is affected.
- Version 17.16.1a is affected.
- Version 16.12.13 is affected.
- Version 17.15.3 is affected.
- Version 17.9.7 is affected.
- Version 17.12.5 is affected.
- Version 17.15.1y is affected.
- Version 17.9.5e is affected.
- Version 17.12.4a is affected.
- Version 17.15.2a is affected.
- Version 17.15.2c is affected.
- Version 17.15.2b is affected.
- Version 17.12.1z3 is affected.
- Version 17.9.5f is affected.
- Version 17.12.4b is affected.
- Version 17.12.5a is affected.
- Version 17.18.1 is affected.
- Version 17.12.6 is affected.
- Version 17.12.1z4 is affected.
- Version 17.9.8 is affected.
- Version 17.9.7a is affected.
- Version 17.15.3a is affected.
- Version 17.15.4 is affected.
- Version 17.12.5b is affected.
- Version 17.15.3b is affected.
- Version 16.12.14 is affected.
- Version 17.18.1z is affected.
- Version 17.9.7b is affected.
- Version 17.12.5c is affected.
- Version 26.1.1 is affected.
- Version 17.18.1a is affected.
- Version 17.15.4a is affected.
- Version 17.18.2 is affected.
- Version 17.18.1w is affected.
- Version 17.15.4b is affected.
- Version 17.12.6a is affected.
- Version 17.12.7 is affected.
- Version 17.15.4c is affected.
- Version 17.9.9 is affected.
- Version 17.12.5d is affected.
- Version 16.12.15 is affected.
- Version 17.15.4s1 is affected.
- Version 17.15.5 is affected.
- Version 17.12.1z5 is affected.
- Version 17.18.1x is affected.
- Version 17.12.1z6 is affected.
- Version 17.15.4d is affected.
- Version 17.12.6b is affected.
- Version 17.4.1c is affected.
- Version 17.15.5a is affected.
- Version 17.18.1y is affected.
- Version 17.12.7a is affected.
- Version 17.18.3 is affected.
- Version 17.12.7b is affected.
- Version 17.18.3a is affected.
- Version 26.1.1a is affected.
- Version 17.15.7 is affected.
- Version 16.12.16 is affected.