CVE-2026-106307 in Chrome
Summary
by MITRE • 10/06/2026
Incorrect authorization in Network in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to bypass system access restrictions via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an incorrect authorization issue within Google Chrome prior to version 155.0.8059.39 represents a critical failure in the browser's process isolation and privilege management mechanisms. This flaw specifically affects the network service, which is responsible for handling all HTTP requests on behalf of renderer processes. In modern browsers like Chrome, security relies heavily on the principle of least privilege and strict sandboxing to prevent compromised components from accessing sensitive system resources or user data. The architecture typically isolates web content in a restricted renderer process while delegating potentially dangerous operations, such as network access, to higher-privilege services. When this separation is breached due to improper authorization checks, it undermines the fundamental security model that protects users from malicious websites and exploits.
The technical root cause of this vulnerability lies in the validation logic governing how renderer processes request resources through the network service. A crafted HTML page could exploit a flaw where the browser failed to correctly verify whether the requesting process had the necessary permissions to access specific system-level APIs or external resources. By leveraging this misconfiguration, an attacker who has already achieved code execution within a sandboxed renderer process can escalate their privileges by bypassing these restrictions. This allows the malicious script to perform actions that should be prohibited in a sandboxed environment, such as accessing local network interfaces, reading sensitive cookies from other origins, or interacting with internal browser services without proper authentication tokens. The severity is classified as medium because while it requires an initial compromise of the renderer process, which often necessitates exploiting another vulnerability first, the ability to bypass system access restrictions significantly expands the attack surface and potential impact of that initial foothold.
From a threat modeling perspective, this flaw aligns with CWE-269, Improper Privilege Management, as it involves a failure to enforce proper authority for specific actions within the application's architecture. Furthermore, in the context of the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Defense Evasion and Lateral Movement within the browser environment. An attacker leveraging this flaw could potentially exfiltrate data from other tabs or windows that share the same network service instance, effectively breaking the cross-origin isolation model. This can lead to unauthorized access to sensitive user information, session hijacking, or further exploitation of internal services that are not designed to be accessible by untrusted web content. The operational impact is significant for users who rely on Chrome's sandboxing to mitigate risks from malicious websites, as it reduces the effectiveness of these protections against sophisticated multi-stage attacks.
Mitigation strategies primarily involve updating Google Chrome to version 155.0.8059.39 or later, where this authorization logic has been corrected and hardened. Users should ensure that automatic updates are enabled to receive security patches promptly as they become available. For enterprise environments, administrators can enforce update policies through group policy settings to guarantee consistent patching across all endpoints. Additionally, users can reduce their exposure by employing browser extensions that enhance sandboxing or restrict network permissions for untrusted sites, although these measures do not replace the need for a patched binary. Security teams should also monitor for indicators of compromise related to renderer process exploitation and abnormal network activity originating from browser processes, as such behavior may indicate an attempt to leverage this specific authorization flaw in conjunction with other vulnerabilities.