Vulnerability in Cisco Identity Services Engine Software

CVE-2026-20071

A vulnerability in the SSID bring-your-own-device (BYOD) onboarding workflow of Cisco ISE could allow an unauthenticated, adjacent attacker to hijack the onboarding session of another user and access protected 802.1X networks.   This vulnerability is due to insufficient authentication checks that are performed while a user is being onboarded. An attacker could exploit this vulnerability by spoofing the legitimate user and triggering a redirection to the guest web portal. A successful exploit could allow the attacker to take over the user session and gain access to the protected 802.1X network.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-20071: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20071?
CVE-2026-20071 is a low-severity vulnerability in Cisco Identity Services Engine Software, classified under Authentication Bypass by Spoofing. CVSS score: 3.8/10. Published 2026-09-16.
How severe is CVE-2026-20071?
Low severity. CVSS v3 base score is 3.8 out of 10.