9.8

CVE-2026-20184: cisco cisco webex meetings Improper Certificate Validation

CVSS: 9.8v3.1CriticalAwaiting analysis
Published 15-04-2026Last modified 16-04-2026
Open JSON

Vulnerability summary

CVE-2026-20184 is a critical (CVSS 9.8) Improper Certificate Validation vulnerability in cisco cisco webex meetings. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 42.8% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.52%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 15-04-2026
    PublishedVulnerability first disclosed.
  2. 16-04-2026
    Last modifiedVulnerability information updated.

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. 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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.52%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

0.00 pp

From 0.52% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.52%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco1 product
  • cisco webex meetings39.7.7 | 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

1 vendor · 1 product

References

1 links