TI-2026-16389 Aliases CVE-2026-20184 GHSA-hh5g-g7m5-5vxv

Cisco Webex Meetings Certificate Validation Vulnerability

MEDIUM 49CWE-295Published 2026-04-15 · Updated 2026-04-16

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Spoofing
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-295.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.0052 44th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco Webex Meetings	39.7.7; 39.9; 40.4.10; 39.6; 40.6.2; 39.8.2; 39.8.4; 40.1; 39.11; 39.7.4; 39.9.1; 40.4; 40.6; 39.7; 39.8; 39.8.3; 40.2; 39.10; 42.6; 42.7; 42.8; 42.9; 42.10; 42.11; 42.12; 43.1; 43.2; 43.3; 43.4; 43.4.1; 43.4.2; 43.5.0; 43.6.0; 43.6.1; 43.7; 43.8; 43.9; 43.10; 43.11; 43.12; 44.1; 44.2; 44.3; 44.4; 44.5; 44.6; 44.7; 44.8; 44.9; 44.10; 44.11; 44.12; 45.1; 45.2; 45.3; 45.4	—	No fix listed	CNA

Cisco Webex Meetings VendorCisco Affected 39.7.7; 39.9; 40.4.10; 39.6; 40.6.2; 39.8.2; 39.8.4; 40.1; 39.11; 39.7.4; 39.9.1; 40.4; 40.6; 39.7; 39.8; 39.8.3; 40.2; 39.10; 42.6; 42.7; 42.8; 42.9; 42.10; 42.11; 42.12; 43.1; 43.2; 43.3; 43.4; 43.4.1; 43.4.2; 43.5.0; 43.6.0; 43.6.1; 43.7; 43.8; 43.9; 43.10; 43.11; 43.12; 44.1; 44.2; 44.3; 44.4; 44.5; 44.6; 44.7; 44.8; 44.9; 44.10; 44.11; 44.12; 45.1; 45.2; 45.3; 45.4 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-20184
2026-10-03 Alias added: GHSA-hh5g-g7m5-5vxv

References

Other 1

cisco-sa-webex-cui-cert-8jSZYhWL

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TI-2026-53489 Cisco Secure Email Gateway SQL Injection Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16388 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16344 Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0

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Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences