What is CVE-2026-20040?

CVE-2026-20040 is a high-severity vulnerability in Cisco Ios Xr Software, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-03-11.

How severe is CVE-2026-20040?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Cisco Ios Xr Software

CVE-2026-20040

A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient v…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.001 (16.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Cisco Ios Xr Software — versions 6.5.3, 6.5.29, 6.5.1

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

cisco-sa-iosxr-privesc-bF8D5U4W

Frequently asked questions

What is CVE-2026-20040?: CVE-2026-20040 is a high-severity vulnerability in Cisco Ios Xr Software, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-03-11.
How severe is CVE-2026-20040?: High severity. CVSS v3 base score is 8.8 out of 10.