CVE-2026-17803 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient validation of untrusted input in Save to Drive in Google Chrome prior to 151.0.7922.72 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted PDF file. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical sandbox escape vector within Google Chrome's Save to Drive functionality that existed prior to version 151.0.7922.72. The flaw stems from inadequate input validation when processing untrusted data, specifically within the PDF handling component of the browser's renderer process. When a malicious actor successfully compromises the renderer process through separate attack vectors, they can craft a specially designed PDF file that exploits this validation weakness to break out of the sandboxed environment.
The technical nature of this vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how insufficient sanitization of user-supplied data can lead to privilege escalation. The attack scenario requires an initial compromise of the renderer process, typically achieved through other means such as zero-day exploits in PDF rendering libraries or browser components. Once this foothold is established, the attacker leverages the Save to Drive functionality to execute malicious code that bypasses Chrome's security boundaries.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to potentially access sensitive user data, modify system files, and establish persistent access within the victim's environment. The sandbox escape capability means that even if other browser protections remain intact, the attacker gains unrestricted access to the underlying operating system resources. This represents a significant risk for users who frequently interact with PDF documents from untrusted sources.
Organizations should prioritize immediate patching of affected Chrome versions and implement additional monitoring for suspicious PDF handling activities within their networks. The mitigation strategy should include maintaining up-to-date browser versions, implementing network-based protections such as web application firewalls, and conducting regular security assessments of PDF processing workflows. From an ATT&CK framework perspective, this vulnerability maps to techniques involving sandbox evasion and privilege escalation, specifically T1055.001 for process injection and T1497.001 for virtualization or sandbox escaping. Security teams should also consider implementing behavioral monitoring solutions that can detect anomalous PDF processing patterns indicative of exploitation attempts.
The vulnerability underscores the importance of comprehensive input validation across all browser components, particularly those handling untrusted data from external sources. Regular security audits of rendering engines and document processors should be conducted to identify similar validation gaps. Additionally, organizations should maintain robust incident response procedures specifically designed to handle browser-based sandbox escapes, as these attacks often require specialized forensic analysis to properly investigate and contain.