CVE-2026-106222 in Chrome
Summary
by MITRE • 10/06/2026
Incorrect authorization in Sync in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an incorrect authorization flaw within the synchronization subsystem of Google Chrome, specifically in versions prior to 155.0.8059.39, represents a significant breach in access control mechanisms that governs how user data is transmitted and processed across devices. This issue stems from a failure in the application logic to properly validate whether an incoming request or network packet possesses the necessary credentials or permissions to access specific synchronization endpoints. In modern web browsers, the sync service acts as a critical bridge between local browser state and cloud-stored user profiles, handling sensitive data such as bookmarks, passwords, browsing history, and extensions. When authorization checks are bypassed or incorrectly implemented within this pipeline, it creates an avenue for remote attackers to exploit trust relationships that should be strictly enforced by cryptographic tokens and session management protocols.
From a technical perspective, the flaw likely involves improper validation of authentication headers or session identifiers during the synchronization handshake process. An attacker capable of crafting specific network traffic can manipulate these parameters to impersonate a legitimate user or trick the browser into accepting unauthorized data requests. This type of vulnerability is classified under CWE-285, which denotes Improper Authorization, indicating that the software does not perform correct checks before allowing access to restricted resources. The ability to craft network traffic suggests that the attack vector relies on manipulating HTTP/HTTPS request structures, potentially exploiting race conditions or logic errors in how Chrome processes incoming synchronization payloads from its servers or peer-to-peer sync channels.
The operational impact of this vulnerability is severe due to the nature of the data involved. Successful exploitation allows a remote attacker to obtain sensitive information that has been synchronized with Google's infrastructure. This could include personal identification details, financial credentials stored in password managers, private browsing history, and potentially session cookies that facilitate further account takeover attacks. Because Chrome syncs data across all devices linked to an account, compromising one device through this vulnerability can lead to the exposure of sensitive information on multiple platforms, including desktop computers, mobile phones, and tablets. The medium severity rating assigned by Chromium reflects the potential for significant privacy breaches while acknowledging that full system compromise or arbitrary code execution is not directly facilitated by this specific flaw.
This incident aligns with several tactics within the MITRE ATT&CK framework, particularly those related to Credential Access and Collection. Attackers may leverage techniques such as Browser Session Hijacking (T1539) or Unsecured Credentials Storage if the vulnerability exposes stored secrets in plaintext or weakly encrypted formats during transmission. Furthermore, the exploitation of synchronization mechanisms can be viewed through the lens of Data Exfiltration over C2 Channels (T1048), where sensitive data is smuggled out via seemingly legitimate browser sync traffic, making detection by traditional network security monitoring tools more difficult due to the use of standard HTTPS ports and trusted domains.
Mitigation strategies for this vulnerability primarily involve immediate software updates. Users must upgrade Google Chrome to version 155.0.8059.39 or later, where the authorization logic in the sync service has been corrected to enforce strict validation of all incoming requests. For organizations managing enterprise deployments, it is crucial to ensure that endpoint protection platforms are updated and that browser policies restrict auto-updates if necessary, though automatic updates remain the most effective defense against such zero-day style exploits. Additionally, users should enable two-factor authentication on their Google accounts to add an extra layer of security, ensuring that even if sensitive data is exfiltrated via this vulnerability, unauthorized access to the actual account remains difficult for attackers relying solely on stolen credentials or session tokens derived from the sync breach.