CVE-2026-20273
High
Description
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 a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20273 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-20.
SeverityHigh
CVSS8.6
Exploit probability—
Product
Cisco Ios Xe
PublishedAug 5, 2026
First seenAug 5, 2026
Weakness typeCWE-20Improper input validation
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| cisco ios_xe | 16.6.2, 16.6.3, 16.6.4, 16.6.4a, 16.6.4s, 16.6.5, 16.6.5a, 16.6.5b, 16.6.6, 16.6.7, 16.6.7a, 16.6.8, 16.6.9, 16.6.10, 16.7.1, 16.7.1a, 16.7.1b, 16.7.2, 16.7.3, 16.7.4, 16.8.1, 16.8.1a, 16.8.1b, 16.8.1c, 16.8.1d, 16.8.1e, 16.8.1s, 16.8.2, 16.8.3, 16.9.1, 16.9.1a, 16.9.1b, 16.9.1c, 16.9.1d, 16.9.1s, 16.9.2, 16.9.2a, 16.9.2s, 16.9.3, 16.9.3a, 16.9.3h, 16.9.3s, 16.9.4, 16.9.4c, 16.9.5, 16.9.5f, 16.9.6, 16.9.7, 16.9.8, 16.9.8a, 16.9.8b, 16.10.1, 16.10.1a, 16.10.1b, 16.10.1c, 16.10.1d, 16.10.1e, 16.10.1f, 16.10.1g, 16.10.1s, 16.10.2, 16.10.3, 16.11.1, 16.11.1a, 16.11.1b, 16.11.1c, 16.11.1s, 16.11.2, 16.12.1, 16.12.1a, 16.12.1c, 16.12.1s, 16.12.1t, 16.12.1w, 16.12.1x, 16.12.1y, 16.12.1z, 16.12.1z1, 16.12.1z2, 16.12.2, 16.12.2a, 16.12.2s, 16.12.2t, 16.12.3, 16.12.3a, 16.12.3s, 16.12.4, 16.12.4a, 16.12.5, 16.12.5a, 16.12.5b, 16.12.6, 16.12.6a, 16.12.7, 16.12.8, 16.12.9, 16.12.10, 16.12.10a, 16.12.11, 16.12.12, 16.12.13, 16.12.14, 16.12.15, 16.12.16, 17.1.1, 17.1.1a, 17.1.1s, 17.1.1t, 17.1.2, 17.1.3, 17.2.1, 17.2.1a, 17.2.1r, 17.2.1v, 17.2.2, 17.2.3, 17.3.1, 17.3.1a, 17.3.1w, 17.3.1x, 17.3.1z, 17.3.2, 17.3.2a, 17.3.3, 17.3.3a, 17.3.4, 17.3.4a, 17.3.4b, 17.3.4c, 17.3.5, 17.3.5a, 17.3.5b, 17.3.6, 17.3.7, 17.3.8, 17.3.8a, 17.4.1, 17.4.1a, 17.4.1b, 17.4.1c, 17.4.2, 17.4.2a, 17.5.1, 17.5.1a, 17.6.1, 17.6.1a, 17.6.1x, 17.6.1z, 17.6.1z1, 17.6.2, 17.6.3, 17.6.3a, 17.6.4, 17.6.5, 17.6.5a, 17.6.6, 17.6.6a, 17.6.7, 17.6.8, 17.6.8a, 17.7.1, 17.7.1a, 17.7.1b, 17.7.2, 17.8.1, 17.8.1a, 17.9.1, 17.9.1a, 17.9.1w, 17.9.1x, 17.9.1x1, 17.9.1y, 17.9.1y1, 17.9.2, 17.9.2a, 17.9.3, 17.9.3a, 17.9.4, 17.9.4a, 17.9.5, 17.9.5a, 17.9.5b, 17.9.5c, 17.9.5d, 17.9.5e, 17.9.5f, 17.9.6, 17.9.6a, 17.9.7, 17.9.7a, 17.9.7b, 17.9.8, 17.9.9, 17.10.1, 17.10.1a, 17.10.1b, 17.11.1, 17.11.1a, 17.12.1, 17.12.1a | — |
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