CVE-2026-17844 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient validation of untrusted input in Cast in Google Chrome prior to 151.0.7922.72 allowed an attacker on the local network segment to leak cross-origin data via malicious network traffic. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/31/2026
This vulnerability represents a critical security flaw in Google Chrome's handling of untrusted input within its casting functionality, specifically affecting versions prior to 151.0.7922.72. The issue stems from inadequate validation mechanisms that fail to properly sanitize or verify data originating from remote network sources, creating a pathway for malicious actors to exploit the system. The vulnerability manifests when Chrome processes casting requests from untrusted network segments, allowing attackers to manipulate input parameters in ways that bypass expected security boundaries.
The technical implementation flaw lies in Chrome's insufficient sanitization of network traffic data during casting operations, which violates fundamental principles of input validation and secure coding practices. This weakness creates a cross-origin data leakage scenario where an attacker positioned on the same local network segment can craft malicious network packets designed to exploit the vulnerable casting infrastructure. The vulnerability specifically targets the validation mechanisms that should ensure data integrity and origin verification before processing casting requests.
From an operational perspective, this vulnerability enables attackers to execute cross-site data exfiltration attacks by leveraging their position within the local network segment. The medium severity classification reflects the requirement for local network access but emphasizes the potential for significant data leakage across different origins. Attackers can exploit this weakness to access sensitive information from other domains or origins that would normally be protected by browser security policies, effectively bypassing same-origin policy enforcement mechanisms.
The vulnerability aligns with CWE-20, which addresses "Improper Input Validation" and represents a classic example of insufficient sanitization of untrusted data. This weakness falls under the broader category of injection vulnerabilities where malicious input is processed without proper validation, potentially leading to unauthorized access or data disclosure. The attack vector specifically relates to network-based exploitation where attackers manipulate traffic patterns to trigger the vulnerability, making it particularly concerning for enterprise environments where local network segmentation may be insufficient.
Security professionals should implement immediate mitigations including updating Chrome installations to version 151.0.7922.72 or later, which contains patches addressing this specific validation flaw. Network administrators should also consider implementing additional traffic filtering rules to limit casting protocol access and monitor for unusual network patterns that might indicate exploitation attempts. The remediation process should include comprehensive testing of casting functionality to ensure proper input validation mechanisms are operational and that no similar vulnerabilities exist in related components.
Organizations should review their network segmentation policies and implement proper access controls to limit which devices can initiate casting operations, as this vulnerability requires local network proximity for exploitation. The incident highlights the importance of robust input validation in web browsers and demonstrates how seemingly minor implementation flaws in security-critical components can create significant attack vectors. This vulnerability serves as a reminder of the critical need for continuous security assessment and timely patch management across all browser components, particularly those handling cross-origin communications and network protocols.
The threat landscape surrounding this vulnerability indicates that attackers with local network access can leverage it for reconnaissance and data exfiltration activities. Attackers may use this weakness to gather information about connected devices, access cached content from other origins, or potentially escalate privileges within the affected browser environment. The medium severity classification suggests that while exploitation requires specific network conditions, the potential impact on user privacy and data security is significant enough to warrant immediate attention.
From a compliance perspective, this vulnerability may affect organizations subject to regulations requiring secure handling of user data and cross-origin protection mechanisms. The remediation process should include thorough testing of browser configurations and implementation of monitoring solutions that can detect anomalous casting behavior or unauthorized access attempts. Security teams should also consider implementing network-based intrusion detection systems that can identify suspicious traffic patterns associated with this specific exploitation technique, particularly in environments where multiple origins are accessed through shared network infrastructure.
The vulnerability demonstrates the complex security challenges inherent in modern browser architectures where components must balance functionality with security requirements. Proper validation of untrusted input remains a fundamental requirement for preventing data leakage and maintaining user privacy across different origin boundaries. Organizations should treat this as a wake-up call to review all input handling mechanisms within their browser configurations and ensure comprehensive testing of security features that protect against cross-origin attacks.
This specific vulnerability affects Google Chrome's implementation of casting protocols, which represent an increasingly common feature in modern browsers for sharing content across devices. The flaw underscores the need for robust validation mechanisms in all network-facing components of web browsers, particularly those handling external data streams or cross-origin communications. The security implications extend beyond simple data leakage to potential privacy violations and information disclosure that could impact user trust in browser-based applications and services.