Vulnerability in Cisco iOS Xr Software
CVE-2026-20276
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-2026-20276 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-691.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (17.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Cisco iOS Xr Software — versions 6.5.26, 24.4.1, 7.5.52
- Cisco iOS Xr — versions 24.1.1, 24.1.2, 24.2.1
Weakness classification (CWE)
References
- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-… (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Not Applicable)
Frequently asked questions
- What is CVE-2026-20276?
- CVE-2026-20276 is a high-severity vulnerability in Cisco iOS Xr Software, classified under CWE-691. CVSS score: 8.6/10. Published 2026-09-02.
- How severe is CVE-2026-20276?
- High severity. CVSS v3 base score is 8.6 out of 10.