CVE-2026-106214 in Chrome
Summary
by MITRE • 10/06/2026
Information leak in Proxy in Google Chrome on on Windows prior to 155.0.8059.39 allowed an adjacent attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as a high-severity issue within the Chromium-based Proxy implementation in Google Chrome for Windows versions prior to 155.0.8059.39 represents a critical failure in information handling during network request processing. This flaw allows an adjacent attacker, typically defined as another user on the same local system or potentially a malicious application running with similar privileges, to exploit improper data management within the proxy layer. The core technical deficiency lies in how Chrome handles sensitive context and credentials when routing traffic through configured proxies. Specifically, the browser fails to adequately sanitize or isolate information associated with one security origin from being inadvertently exposed to another context during the negotiation of proxy connections. This misconfiguration enables an attacker who can inject crafted network traffic into the local environment to intercept or infer details that should remain confidential, such as authentication tokens, internal IP addresses, or specific user session identifiers.
From a technical perspective, this vulnerability aligns with CWE-209, which describes the generation of error messages containing sensitive information, and more broadly with CWE-200, where an attacker gains access to unauthorized data through improper exposure mechanisms. The attack vector relies on the ability to manipulate network traffic in proximity to the victim's browsing session. By crafting specific requests that trigger the flawed proxy logic, the adversary can cause Chrome to leak metadata or partial responses back into a context accessible by the local attacker. This is particularly dangerous because it bypasses standard cross-origin resource sharing protections and sandbox boundaries, as the leakage occurs at the network interface level before content rendering begins. The severity rating of High reflects the potential for significant data exfiltration without requiring remote code execution privileges on the target machine.
The operational impact of this vulnerability extends beyond simple privacy violations. An adjacent attacker could use the leaked information to facilitate further attacks, such as session hijacking or privilege escalation within local applications that rely on similar authentication mechanisms. For enterprise environments where Chrome is deployed with specific proxy configurations for traffic inspection and security monitoring, this flaw undermines the integrity of network segmentation strategies. Attackers can map internal network topologies by observing how different requests are routed and what responses are returned, effectively turning a standard web browser into an active reconnaissance tool against local infrastructure. This capability compromises the confidentiality guarantees expected from modern browsers and erodes trust in the security model that isolates user data from malicious processes running on the same endpoint.
Mitigation strategies must prioritize immediate patching to version 155.0.8059.39 or later, where Google has addressed the underlying logic errors in the proxy handling subsystem. Organizations should enforce strict update policies across all Windows endpoints using Chrome to ensure this vulnerability is closed before it can be exploited by automated tools targeting unpatched systems. Additionally, administrators should review local network configurations to minimize the attack surface for adjacent threats. Implementing host-based firewalls that restrict outbound traffic from browser processes to only necessary proxy endpoints can limit the effectiveness of crafted traffic attacks. Security teams should also monitor for anomalous network patterns indicative of information leakage probes and ensure that endpoint detection and response solutions are configured to alert on unusual data exfiltration attempts originating from web browsers.