CVE-2026-20271

HIGHCVSS 8.6/10EPSS 0.25%

Last modified

CVE-2026-20271 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. 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-2026-20271 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-691.  . EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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 software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20271 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-691.  

Metrics

CVSS 3.1
8.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability
0.25%

16.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoIos Xe16.6.2
CiscoIos Xe16.6.3
CiscoIos Xe16.6.4
CiscoIos Xe16.6.4a
CiscoIos Xe16.6.4s
CiscoIos Xe16.6.5
CiscoIos Xe16.6.5a
CiscoIos Xe16.6.5b
CiscoIos Xe16.6.6
CiscoIos Xe16.6.7
CiscoIos Xe16.6.7a
CiscoIos Xe16.6.8
CiscoIos Xe16.6.9
CiscoIos Xe16.6.10
CiscoIos Xe16.7.1
CiscoIos Xe16.7.1a
CiscoIos Xe16.7.1b
CiscoIos Xe16.7.2
CiscoIos Xe16.7.3
CiscoIos Xe16.7.4
CiscoIos Xe16.8.1
CiscoIos Xe16.8.1a
CiscoIos Xe16.8.1b
CiscoIos Xe16.8.1c
CiscoIos Xe16.8.1d
CiscoIos Xe16.8.1e
CiscoIos Xe16.8.1s
CiscoIos Xe16.8.2
CiscoIos Xe16.8.3
CiscoIos Xe16.9.1
CiscoIos Xe16.9.1a
CiscoIos Xe16.9.1b
CiscoIos Xe16.9.1c
CiscoIos Xe16.9.1d
CiscoIos Xe16.9.1s
CiscoIos Xe16.9.2
CiscoIos Xe16.9.2a
CiscoIos Xe16.9.2s
CiscoIos Xe16.9.3
CiscoIos Xe16.9.3a
CiscoIos Xe16.9.3h
CiscoIos Xe16.9.3s
CiscoIos Xe16.9.4
CiscoIos Xe16.9.4c
CiscoIos Xe16.9.5
CiscoIos Xe16.9.5f
CiscoIos Xe16.9.6
CiscoIos Xe16.9.7
CiscoIos Xe16.9.8
CiscoIos Xe16.9.8a

Showing 50 of 267 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-20271?
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-2026-20271 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-691.  
How severe is CVE-2026-20271?
CVE-2026-20271 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.
How do I fix CVE-2026-20271?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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Source: NVD / NIST