CVE-2026-82809 in Vision for YouTube Extension
Summary
by MITRE • 08/31/2026
A security flaw has been discovered in vidIQ Vision for YouTube Extension 3.199.0 on Chrome. The affected element is the function window.addEventListener of the component postMessage Handler. Performing a manipulation of the argument vidiqEvent results in information disclosure. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The vendor explains: "At this time, vidIQ does not accept security vulnerability submissions, and we do not have a bug bounty program in place."
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Analysis
by VulDB Data Team • 08/31/2026
The discovery of a critical information disclosure vulnerability within the vidIQ Vision for YouTube Extension version 3.199.0 on Google Chrome highlights significant risks associated with browser extension architectures that rely heavily on inter-process communication mechanisms. The specific flaw resides in the postMessage handler component, which is responsible for managing asynchronous messages between different parts of an application or between a web page and its embedded content. In this instance, the vulnerability affects the window.addEventListener function when it processes events triggered by the vidiqEvent argument. This architectural design choice creates a surface area where improper validation of incoming message data can lead to unintended exposure of sensitive internal state information. The core technical flaw is rooted in insufficient input sanitization and type checking within the event listener, allowing an attacker who controls or influences the content of the vidiqEvent parameter to manipulate how the extension processes subsequent actions. This lack of strict boundary enforcement between trusted and untrusted sources enables a cross-site scripting-like scenario where malicious scripts can inject payloads that are executed with the elevated privileges granted to browser extensions.
From a technical perspective, this vulnerability aligns closely with CWE-20 Improper Input Validation and CWE-79 Cross-site Scripting within the context of extension APIs. The postMessage API is designed for secure communication between browsing contexts, but it requires developers to explicitly validate the origin of incoming messages and sanitize their content before processing. In vidIQ Vision 3.199.0, the handler fails to adequately verify that the vidiqEvent argument originates from a trusted source or conforms to expected data structures. Consequently, an attacker can craft a malicious webpage containing JavaScript code that sends a specifically formatted postMessage request to the extension's background page or content script. By manipulating the event payload, the attacker can trigger side effects that cause the extension to expose internal variables, user session tokens, browsing history details, or other proprietary data structures back to the originating context. This mechanism effectively bypasses standard browser security models because extensions operate with higher privileges than regular web pages, including access to cookies, local storage, and potentially network requests initiated by the host page.
The operational impact of this vulnerability is severe due to its remote exploitability and the availability of public proof-of-concept code. Since the attack can be carried out remotely without user interaction beyond visiting a malicious website or being redirected via drive-by techniques, it poses a significant threat to end-users who rely on vidIQ for YouTube analytics and optimization. Successful exploitation could lead to comprehensive information disclosure, allowing attackers to harvest sensitive data such as authentication cookies that facilitate account takeover attacks. Furthermore, the exposure of internal extension logic may aid in crafting more sophisticated follow-up exploits targeting other components of the browser ecosystem or related services integrated with YouTube accounts. The fact that exploit code has already been released publicly accelerates the risk landscape, enabling less skilled threat actors to leverage these techniques for large-scale data harvesting campaigns against content creators and marketers who use the tool extensively.
The vendor's stated policy regarding security vulnerability submissions presents a unique challenge in mitigating this issue. VidIQ explicitly states that it does not accept security vulnerability reports nor maintain a bug bounty program, which removes standard channels for coordinated disclosure and patching through official support structures. This approach forces users to rely on community-driven mitigation strategies until the vendor decides to address the flaw independently or releases an updated version with corrected code. In such scenarios, defensive measures must focus on limiting exposure rather than relying solely on upstream fixes. Users should consider disabling the extension when not in active use to reduce the attack surface available for remote exploitation. Additionally, employing browser security extensions that restrict postMessage origins or block scripts from accessing specific domains can provide a layer of defense against this type of injection-based information leak.
Industry standards such as MITRE ATT&CK classify this behavior under techniques related to Collection and Exfiltration over Alternative Protocols, specifically leveraging client-side scripting for data theft. The vulnerability exemplifies the dangers inherent in complex browser extensions that bridge multiple security domains without rigorous validation layers. To mitigate similar risks across the broader ecosystem of web applications and extensions, developers must adhere strictly to secure coding practices outlined by OWASP and NIST guidelines. This includes implementing strict origin checks using event.origin properties, validating message types against a whitelist of expected events, and avoiding direct execution or evaluation of untrusted data strings. For organizations deploying such tools across employee devices, network-level filtering and endpoint detection systems that monitor for anomalous postMessage traffic patterns can offer additional visibility into potential exploitation attempts before significant damage occurs.