CVE-2026-66641 in Video Conferencing with Zoom Plugin
Summary
by MITRE • 08/18/2026
Contributor Cross Site Scripting (XSS) in Video Conferencing with Zoom <= 4.6.8 versions.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified as Contributor Cross-Site Scripting within Zoom client versions prior to or equal to 4.6.8 represents a significant security flaw affecting the integrity of user sessions and potentially leading to account compromise. This specific type of cross-site scripting, often categorized under CWE-79 in the Common Weakness Enumeration standard, arises from insufficient input validation when processing data contributed by meeting participants. In video conferencing platforms like Zoom, contributors include not only those presenting content but also users interacting via chat, polls, or other collaborative features embedded within the application interface. The flaw exists because the client software fails to properly sanitize user-supplied input before rendering it in a web view component that is integral to the meeting experience.
When an attacker crafts malicious script payloads and injects them into fields such as the participant name, chat messages, or presentation titles, these scripts are executed within the context of the Zoom application's internal browser engine rather than being displayed as plain text. This execution environment typically possesses elevated privileges compared to a standard web browser sandbox due to its integration with local system resources and authentication tokens stored on the user device. Consequently, an attacker can exploit this weakness to perform actions such as stealing session cookies, capturing keystrokes, or redirecting users to phishing sites without their knowledge. The impact is particularly severe because it allows for persistent attacks if the malicious content is saved within meeting history or shared files accessible by other participants later.
From a tactical perspective, this vulnerability aligns with MITRE ATT&CK technique T1059, which covers Command and Scripting Interpreter execution, specifically through web browser-based mechanisms. The attack vector relies on social engineering to convince users to join meetings containing the malicious payload or to interact with compromised meeting content. Once executed, the script can exfiltrate sensitive information including personal identifiable information, corporate secrets discussed in the meeting, or credentials stored within the application's local storage. This undermines the confidentiality and integrity guarantees expected from enterprise-grade communication tools, potentially facilitating further lateral movement if session tokens are harvested for use against other services where single sign-on is enabled.
Mitigation strategies primarily involve upgrading to a patched version of Zoom that addresses these input validation deficiencies by implementing strict output encoding and context-aware sanitization techniques. Organizations should enforce endpoint security policies that restrict the execution of arbitrary scripts within application containers unless explicitly whitelisted. Additionally, user awareness training remains critical; participants must be educated to avoid interacting with unknown meeting links or content from unverified sources until patches are applied. Security teams should also monitor for anomalous network traffic originating from Zoom client processes, as this may indicate active exploitation attempts targeting the vulnerability in older deployments that have not yet been updated.