Vulnerability in Cisco Nx-Os Software
CVE-2025-20191
A vulnerability in the Switch Integrated Security Features (SISF) of Cisco IOS Software, Cisco IOS XE Software, Cisco NX-OS Software, and Cisco Wireless LAN Controller (WLC) AireOS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to the incorrect handling of DHCPv6 packets. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (14.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Cisco Nx-Os Software — versions 8.2(5), 7.3(5)D1(1), 8.4(2)
- Cisco Wireless Lan Controller (Wlc) — versions 8.10.112.0, 8.8.120.0, 8.3.143.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-20191?
- CVE-2025-20191 is a high-severity vulnerability in Cisco Nx-Os Software, classified under Buffer Access with Incorrect Length Value. CVSS score: 7.4/10. Published 2025-05-07.
- How severe is CVE-2025-20191?
- High severity. CVSS v3 base score is 7.4 out of 10.