XSS in Cisco Firepower Extensible Operating System (Fxos)
CVE-2026-20091
A vulnerability in the web-based management interface of Cisco FXOS Software and Cisco UCS Manager Software could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface…
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.000 (14.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Cisco Firepower Extensible Operating System (Fxos) — versions 2.14.1.131, 2.14.1.143, 2.14.1.163
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.12.2, 9.12.1, 9.12.3
- Cisco Unified Computing System (Managed) — versions 4.0(4h), 4.1(1a), 4.0(1c)
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20091?
- CVE-2026-20091 is a medium-severity vulnerability in Cisco Firepower Extensible Operating System (Fxos), classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-02-25.
- How severe is CVE-2026-20091?
- Medium severity. CVSS v3 base score is 4.8 out of 10.