CiscoCVE-2026-20273
Cisco IOS XE Software: improper input validation
High8.6CVE-2026-20273 · Published Aug 5, 2026 · updated Aug 17, 2026
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.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Cisco IOS XE Software Product | <= 17.2.1a | No fix yet |
| <= 16.12.1y | No fix yet | |
| <= 16.12.3s | No fix yet | |
| <= 16.7.1b | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-20
More Cisco advisories
All Cisco| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Aug 5 | Cisco Catalyst SD-WAN: cleartext secrets | High8.8 | No fix yet |
| Aug 5 | Cisco Catalyst SD-WAN: improper quantity validation | High7.7 | No fix yet |
| Aug 5 | Cisco IOS XE Software: denial of service | Medium4.3 | No fix yet |
| Aug 5 | Cisco Catalyst SD-WAN: link following | Critical9.1 | No fix yet |
| Aug 5 | Cisco IOS XE Software: denial of service | Medium6.3 | No fix yet |
| Aug 5 | Cisco IOS XE Software: denial of service | High8.6 | No fix yet |