Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-20184

Severity CVSS v4.0:
Pending analysis
Type:
CWE-295 Improper Certificate Validation
Publication date:
15/04/2026
Last modified:
17/04/2026

Description

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.<br /> <br /> 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.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.80 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
9.80
Severity 3.x
CRITICAL

References to Advisories, Solutions, and Tools