by Kastro
Paper/Archive/CVE-2026-20184

CVE-2026-20184

Cisco Cisco Webex Meetings — Cisco Webex Meetings Certificate Validation Vulnerability

EPSS 0.5%CVSS 9.8
critical.is priorityof 100
38
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 44.2.442 × 208.8No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

A vulnerability in the integration of single sign-on (SSO) with Control Hub in Cisco Webex Services could have allowed an unauthenticated, remote attacker to impersonate any user within the service. This vulnerability existed because of improper certificate validation. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by connecting to a service endpoint and supplying a crafted token. A successful exploit could have allowed the attacker to gain unauthorized access to legitimate Cisco Webex services.

Affected

ProductAffectedFixed inSource
Cisco Webex Meetings39.7.7–CNA
Cisco Webex Meetings39.9–CNA
Cisco Webex Meetings40.4.10–CNA
Cisco Webex Meetings39.6–CNA
Cisco Webex Meetings40.6.2–CNA
Cisco Webex Meetings39.8.2–CNA
Cisco Webex Meetings39.8.4–CNA
Cisco Webex Meetings40.1–CNA
Cisco Webex Meetings39.11–CNA
Cisco Webex Meetings39.7.4–CNA
Cisco Webex Meetings39.9.1–CNA
Cisco Webex Meetings40.4–CNA

Scores by source

cisco (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refsec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-cui-cert-8jSZYhWL