What’s Vulnerable › Vulnerabilities

CVE-2026-20279: Cisco IOS XR Software Security Hardening Release: September 2026

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-02 · updated 2026-09-18
• Weakness: CWE-284

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20279 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.

Affected products

• Cisco IOS XR Software: 6.5.29, 7.0.1, 6.5.26, 6.5.25, 6.5.28, 6.5.90 (+106)

In the news

• Cisco IOS XR Software Security Hardening Release: September 2026

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxr-qg64NcM
• https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification

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