CVE-2026-106208 in Chrome
Summary
by MITRE • 10/06/2026
Missing authorization in API in Google Chrome prior to 155.0.8059.39 allowed a remote attacker leveraging social engineering to leak sensitive information via a crafted Chrome extension. (Chromium security severity: Medium)
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as missing authorization within the application programming interface of Google Chrome versions prior to 155.0.8059.39 represents a critical flaw in how browser extensions interact with privileged APIs. This issue stems from an insufficient access control mechanism that fails to properly validate whether a requesting extension has been granted the necessary permissions by the user or system policy before executing sensitive operations. In modern web browsers, extensions operate within a sandboxed environment but are often granted elevated privileges based on explicit permission requests made during installation. When these authorization checks are bypassed or improperly implemented, it allows an attacker to exploit this gap through maliciously crafted Chrome extensions that masquerade as legitimate tools while secretly accessing data they should not be able to reach.
The operational impact of this vulnerability is significant because it enables remote attackers to leak sensitive information without direct user interaction beyond the initial installation of the malicious extension. By leveraging social engineering tactics, an attacker can deceive users into installing a seemingly benign or useful browser add-on that contains hidden code designed to exploit the authorization flaw. Once installed, the extension can silently exfiltrate data such as browsing history, cookies, stored passwords, or other personally identifiable information from the victim's profile. This type of attack is particularly dangerous because it relies on trust in the Chrome Web Store ecosystem and user judgment regarding which extensions are safe to install, making detection difficult for traditional security controls that do not monitor extension behavior at runtime.
From a technical perspective, this vulnerability aligns with CWE-285 Improper Authorization, where an application does not properly verify permissions before allowing access to resources or functions. The attack vector is classified under MITRE ATT&CK technique T1059 Command and Scripting Interpreter via browser extensions, which falls within the broader category of client-side attacks such as Client Side Proxy (T1564) for hiding malicious activity. The exploitation requires no remote code execution in the traditional sense but rather abuses legitimate extension APIs to perform unauthorized data access. This highlights a persistent challenge in web security where the boundary between trusted and untrusted content is blurred by the powerful capabilities granted to extensions, necessitating stricter enforcement of permission scopes and runtime checks.
Mitigation strategies for this vulnerability primarily involve updating Google Chrome to version 155.0.8059.39 or later, which includes patches that enforce proper authorization checks within the affected APIs. Organizations should also implement strict extension management policies using enterprise-level browser configuration tools to whitelist only approved extensions and disable sideloading of unverified add-ons. Users are advised to review installed extensions regularly, remove any that are no longer needed, and exercise caution when installing new ones by verifying developer reputation and requested permissions. Additionally, deploying endpoint detection and response solutions capable of monitoring extension behavior can help identify anomalous data access patterns indicative of exploitation attempts before significant damage occurs.