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Cisco Webex Meetings Cross-Site Scripting Vulnerability

mediumCVE-2026-20233
A vulnerability in the web-based user interface of Cisco Webex Meetings could have allowed an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack. Cisco has addressed this vulnerability in the Webex Meetings service, and no customer action is needed. This vulnerability existed because of insufficient validation of user input. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by persuading a user to follow a malicious link. A successful exploit could have allowed the attacker to execute arbitrary script code in the browser of the targeted user or access sensitive, browser-based information. As mentioned, Cisco has addressed this vulnerability in the Webex Meetings service, and no customer action is necessary to update on-premises software or devices. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-xss-jw3NeQzS Security Impact Rating: Medium CVE: CVE-2026-20233

CSIRTS triage

What
A cross-site scripting vulnerability could allow an attacker to execute arbitrary script code.
Who is affected
Users of Cisco Webex Meetings.
Urgency
Remediation is important as it could lead to unauthorized access to sensitive information.
Action
No action needed as Cisco has addressed the vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source
Cisco Security Advisories (INTL · vendor-psirt · site)
Severity
medium
Published
2026-06-03
Exploitation
Not in CISA KEV at last sync

Original advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-xss-jw3NeQzS?vs_f=Cisco%20Security%20Advisory%26vs_cat=Security%20Intelligence%26vs_type=RSS%26vs_p=Cisco%20Webex%20Meetings%20Cross-Site%20Scripting%20Vulnerability%26vs_k=1

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-20233coverage & exploitation statusNVD · CVE.org

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