What is CVE-2026-20104?

CVE-2026-20104 is a medium-severity vulnerability in Cisco Ios Xe Software, classified under Buffer Underwrite. CVSS score: 6.1/10. Published 2026-03-25.

How severe is CVE-2026-20104?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Vulnerability in Cisco Ios Xe Software

CVE-2026-20104

A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugge…

EPSS: 0.001 (17.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Cisco Ios Xe Software — versions 16.12.8, 16.12.6, 16.12.6a

Weakness classification (CWE)

CWE-124 — Buffer Underwrite

References

cisco-sa-xe-secureboot-bypass-B6uYxYSZ

Frequently asked questions

What is CVE-2026-20104?: CVE-2026-20104 is a medium-severity vulnerability in Cisco Ios Xe Software, classified under Buffer Underwrite. CVSS score: 6.1/10. Published 2026-03-25.
How severe is CVE-2026-20104?: Medium severity. CVSS v3 base score is 6.1 out of 10.