CVE-2026-17703 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient policy enforcement in Chrome for iOS in Google Chrome on iOS prior to 151.0.7922.72 allowed a remote attacker to bypass navigation restrictions via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical flaw in the Chrome for iOS browser's policy enforcement mechanisms that could be exploited by remote attackers to circumvent intended navigation restrictions. The issue stems from insufficient validation of HTML content within the browser's security framework, specifically affecting versions prior to 151.0.7922.72. The vulnerability is classified as high severity by Chromium security standards and demonstrates a significant weakness in the browser's content handling and access control implementation.
The technical flaw manifests when a crafted HTML page is loaded into Chrome for iOS, allowing attackers to bypass established navigation restrictions that should normally prevent certain types of web interactions or content access. This occurs due to inadequate policy enforcement within the browser's rendering engine, where maliciously constructed HTML elements can trigger unexpected behavior that circumvents the intended security boundaries. The vulnerability specifically affects how the browser processes and enforces navigation policies for restricted web content.
Operationally, this flaw enables remote attackers to execute unauthorized navigation attempts that would normally be blocked by the browser's security policies. Attackers could potentially redirect users to malicious websites, access restricted resources, or bypass content filtering mechanisms that are fundamental to protecting user privacy and security. The impact extends beyond simple navigation bypasses as it could enable more sophisticated attacks such as phishing attempts, credential theft, or unauthorized data access through manipulated web interactions.
The vulnerability exposes weaknesses in Chrome for iOS's security architecture that relate to policy enforcement mechanisms and HTML content processing. It demonstrates the importance of comprehensive input validation and proper enforcement of security policies across all browser components. This issue aligns with common attack patterns described in the attack technique matrix, particularly those involving privilege escalation through content manipulation. The flaw represents a failure in maintaining consistent security boundaries within the browser environment.
Mitigation efforts should focus on immediate patching to versions 151.0.7922.72 and later, which contain the necessary security fixes for policy enforcement. Organizations should also implement additional network-level controls and content filtering measures as defensive layers. Regular security updates and monitoring for similar policy enforcement vulnerabilities in browser components are essential practices. The fix likely involves strengthening HTML parsing logic and ensuring that navigation restrictions are properly enforced regardless of content manipulation attempts, aligning with established security principles such as least privilege and defense in depth.
This vulnerability highlights the complexity of maintaining robust security in mobile browser environments where multiple security layers must work cohesively. The issue demonstrates how seemingly isolated policy enforcement failures can create significant security risks in web browsing contexts. Proper implementation of security controls requires continuous validation of access restrictions and comprehensive testing of content handling behaviors to prevent exploitation of such vulnerabilities. Organizations should consider implementing additional monitoring for suspicious navigation patterns and user behavior anomalies that might indicate exploitation attempts.