CVE-2026-17864 in Chrome
Summary
by MITRE • 07/30/2026
Inappropriate implementation in Updater in Google Chrome on Mac prior to 151.0.7922.72 allowed a local attacker to perform OS-level privilege escalation via a malicious file. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical privilege escalation flaw within the macOS updater component of Google Chrome versions prior to 151.0.7922.72. The issue stems from inadequate input validation and improper handling of file operations during the update process, creating an avenue for local attackers to elevate their privileges to system level. The vulnerability manifests when the updater component processes malicious files without sufficient sanitization checks, allowing arbitrary code execution with elevated permissions.
The technical implementation flaw resides in how Chrome's macOS updater handles file paths and execution contexts during software updates. Attackers can craft malicious files that exploit the updater's trust model, leveraging the fact that certain update operations are performed with elevated privileges. This weakness aligns with CWE-78 and CWE-20, representing improper input validation and implementation flaws that permit unauthorized privilege escalation. The vulnerability operates at the operating system level where the updater component executes with root privileges, making it particularly dangerous for local attackers who can manipulate the update process.
From an operational perspective, this vulnerability enables a local attacker to gain complete system control without requiring additional attack vectors or user interaction. The medium severity classification by Chromium reflects the relatively straightforward exploitation method that does not require social engineering or complex attack chains. However, the impact is severe as it allows attackers to bypass standard user permission models and execute arbitrary code with system-level privileges. This makes it an attractive target for threat actors seeking persistent access or system compromise.
The attack surface extends beyond simple privilege escalation to include potential data exfiltration, system monitoring, and further lateral movement within compromised networks. Attackers can leverage this vulnerability to install backdoors, modify system files, or establish persistent access points that persist across reboots. The exploitation requires local access to the target system but does not need network connectivity or user interaction, making it particularly stealthy and difficult to detect through traditional network monitoring approaches.
Mitigation strategies should prioritize immediate patching of affected Chrome versions to 151.0.7922.72 or later, which addresses the improper file handling and privilege escalation mechanisms. Organizations should implement additional security controls including endpoint detection and response solutions that monitor for anomalous updater behavior, file system modifications during update processes, and unexpected privilege elevation events. System administrators should also consider restricting local user privileges where possible and implementing application whitelisting policies to prevent unauthorized execution of malicious update components. The remediation aligns with ATT&CK technique T1068 which covers local privilege escalation methods, requiring comprehensive monitoring and access control measures to prevent exploitation.
This vulnerability demonstrates the importance of proper privilege separation in software update mechanisms and highlights the need for robust input validation in system-level components. The flaw represents a failure in the principle of least privilege where update processes should operate with minimal required permissions rather than full system privileges. Security teams should conduct regular audits of update mechanisms across all installed software, particularly those that execute with elevated privileges on target systems, to identify and remediate similar implementation gaps that could lead to privilege escalation attacks.