CVE-2026-17921
Summary
by MITRE • 07/30/2026
Insufficient validation of untrusted input in Navigation in Google Chrome prior to 151.0.7922.72 allowed a remote attacker who had compromised the renderer process to bypass navigation restrictions via a crafted HTML page. (Chromium security severity: Low)
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical weakness in chrome's navigation handling mechanisms that emerged from insufficient input validation within the browser's rendering pipeline. The flaw existed in google chrome versions prior to 151.0.7922.72 and specifically targeted the navigation component that processes user requests and redirects. When an attacker successfully compromised the renderer process, they could craft malicious html pages designed to exploit this validation gap, effectively bypassing established navigation restrictions that should have prevented certain types of redirects or navigational actions.
The technical nature of this vulnerability stems from chrome's failure to properly validate untrusted input during navigation processing within the browser's security boundaries. This represents a classic case where input validation controls were insufficiently implemented at the navigation layer, allowing crafted payloads to circumvent intended security restrictions. The renderer process compromise scenario indicates that attackers had already achieved code execution within chrome's sandboxed environment, but this vulnerability provided them with an additional attack vector to escalate their privileges or expand their control beyond normal navigation boundaries.
The operational impact of this vulnerability extends beyond simple navigation bypasses, as it essentially allows attackers who have already compromised the renderer process to perform unauthorized redirects or navigational actions that should have been restricted by chrome's security policies. This could enable attackers to redirect users to malicious sites, access restricted content areas, or potentially execute additional attacks through manipulated navigation sequences. The chromium security severity classification of low suggests that while the immediate impact may not be catastrophic, the vulnerability represents a significant weakening of chrome's overall security posture.
This flaw aligns with common weaknesses identified in the cwe dictionary under cwe-20, which covers "improper input validation" and specifically relates to scenarios where applications fail to validate input from untrusted sources. The attack pattern closely follows techniques described in the attack tree framework where attackers leverage already compromised components to escalate privileges or expand their attack surface through additional vector exploitation. Organizations should consider implementing layered security controls including regular browser updates, network monitoring for suspicious navigation patterns, and enhanced renderer process isolation measures.
The mitigation strategy requires immediate deployment of chrome version 151.0.7922.72 or later which contains the necessary patches to address this input validation deficiency. Additionally, administrators should implement comprehensive monitoring solutions that can detect unusual navigation behavior patterns within their networks, particularly focusing on redirect sequences that might indicate exploitation attempts. Security teams should also review their existing renderer process hardening measures and consider implementing additional sandboxing controls to limit the potential impact of future compromises.
This vulnerability demonstrates the critical importance of maintaining robust input validation at all layers of browser security architecture, particularly within components that handle user interactions and navigation requests. The flaw serves as a reminder that even when attackers have achieved initial compromise through other vectors, insufficient validation mechanisms can provide additional attack surfaces that significantly amplify the potential damage of security incidents. Organizations should regularly audit their browser security configurations and ensure that all input handling components maintain strict validation controls to prevent similar issues from occurring in their environments.
The technical implications of this vulnerability extend beyond simple bypass scenarios, as it represents a failure in chrome's security model where navigation restrictions are not properly enforced when the renderer process is compromised. This indicates a potential gap in chrome's overall threat model and suggests that similar validation gaps may exist elsewhere within the browser's architecture. Security professionals should conduct comprehensive assessments of their browser security implementations and ensure that all navigation-related components maintain proper input validation controls.
From an industry perspective, this vulnerability reflects ongoing challenges in maintaining secure browser environments where multiple attack vectors and compromise scenarios must be considered simultaneously. The low severity classification does not diminish the importance of addressing this issue promptly, as it represents a potential escalation path that could significantly impact user security when combined with other exploitation techniques. Organizations should maintain updated threat intelligence feeds to monitor for similar vulnerabilities in their browser ecosystems and implement proactive defense measures against known attack patterns.