CVE-2026-20184Cisco Webex Meetings Certificate Validation Vulnerability
- 9.8CriticalCVSS base score
- 0.53%Exploitation in 30 daysEPSS · top 55% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By cisco
- 6 months later
· 6 months later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.53% · top 55% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 39.7.7
- affected 39.9
- affected 40.4.10
- affected 39.6
- affected 40.6.2
- affected 39.8.2
- affected 39.8.4
- affected 40.1
- affected 39.11
- affected 39.7.4
- affected 39.9.1
- affected 40.4
- affected 40.6
- affected 39.7
- affected 39.8
- affected 39.8.3
- affected 40.2
- affected 39.10
- affected 42.6
- affected 42.7
- affected 42.8
- affected 42.9
- affected 42.10
- affected 42.11
- affected 42.12
- affected 43.1
- affected 43.2
- affected 43.3
- affected 43.4
- affected 43.4.1
- affected 43.4.2
- affected 43.5.0
- affected 43.6.0
- affected 43.6.1
- affected 43.7
- affected 43.8
- affected 43.9
- affected 43.10
- affected 43.11
- affected 43.12
- and 16 more
What to do
Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-22971 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20184)Record last updated .