What is CVE-2026-20272?

CVE-2026-20272 is a critical-severity vulnerability in Cisco Ios Xe Software, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 9.8/10. Published 2026-08-05.

How severe is CVE-2026-20272?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Cisco Ios Xe Software

CVE-2026-20272

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 ad…

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Cisco Ios Xe Software — versions 17.2.1a, 16.12.1y, 16.12.3s

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

psirt@cisco.com

Frequently asked questions

What is CVE-2026-20272?: CVE-2026-20272 is a critical-severity vulnerability in Cisco Ios Xe Software, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 9.8/10. Published 2026-08-05.
How severe is CVE-2026-20272?: Critical severity. CVSS v3 base score is 9.8 out of 10.