CVE-2026-87546 in Chrome
Summary
by MITRE • 09/09/2026
Incorrect type conversion or cast in Safebrowsing in Google Chrome on on Mac prior to 153.0.8010.36 allowed a remote attacker to bypass system access restrictions via a crafted file. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an incorrect type conversion or cast within the Safebrowsing component of Google Chrome on Mac operating systems prior to version 153.0.8010.36 represents a subtle but significant logic error in how data types are handled during security checks. This flaw occurs when the browser processes files that trigger safe browsing evaluations, specifically involving scenarios where an attacker can manipulate input parameters such that the expected data type differs from the actual runtime type. In many programming contexts, particularly those underlying Chrome's C++ architecture, implicit or explicit casts between incompatible types can lead to undefined behavior or unintended state changes. When this occurs within a security-critical module like Safebrowsing, which is responsible for validating URLs and file downloads against known malicious databases, it creates an opportunity for attackers to exploit the discrepancy in type handling to bypass intended access controls.
From a technical perspective, this issue aligns with CWE-682, Incorrect Calculation or Conversion, where software performs operations on data using incorrect types, leading to unexpected results. The specific mechanism likely involves a scenario where a crafted file triggers a code path that expects one data structure but receives another due to improper casting. This mismatch can cause the Safebrowsing engine to misinterpret the nature of the request or the associated metadata, potentially causing it to skip critical validation steps or return an incorrect verdict regarding the safety of the content. By carefully crafting input files, a remote attacker could induce this type confusion, effectively tricking the browser into treating malicious content as safe or bypassing restrictions that were designed to prevent such access.
The operational impact of this vulnerability is categorized under CWE-200, Information Exposure, and potentially CWE-798, Use of Hard-coded Credentials if it leads to unauthorized data retrieval, though in this context, the primary concern is the bypass of system access restrictions. An attacker leveraging this flaw could execute remote code or download malicious payloads that would otherwise be blocked by Chrome's security mechanisms. This undermines the integrity of the browser's sandboxing and filtering capabilities, exposing users on Mac systems to potential malware infection, data theft, or further exploitation chains. The severity is rated as Low because successful exploitation likely requires specific conditions regarding file types and user interaction, but it remains a critical concern for maintaining robust endpoint security posture.
This vulnerability maps directly to MITRE ATT&CK technique T1059, Command and Scripting Interpreter, specifically in the context of bypassing application control or execution restrictions through crafted inputs that exploit logic flaws rather than memory corruption. It also relates to T1204, User Execution, as it relies on a user opening or interacting with a crafted file to trigger the type conversion error within the Safebrowsing module. The attack vector is remote, meaning no local access is required initially, but it depends on social engineering elements such as convincing a user to open a specific file that triggers the vulnerable code path in Chrome.
Mitigation strategies primarily involve updating Google Chrome to version 153.0.8010.36 or later, where this type conversion logic has been corrected by the Chromium security team. Administrators should ensure automated update policies are enforced across all Mac endpoints to minimize exposure windows. Additionally, organizations can implement network-level filtering and endpoint detection and response (EDR) solutions that monitor for unusual file downloads or execution patterns associated with Safebrowsing bypass attempts. While this specific flaw is low severity, it highlights the importance of rigorous code review practices focused on type safety and defensive programming techniques to prevent similar logic errors in future releases.