CVE-2026-17831 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient validation of untrusted input in Passwords in Google Chrome prior to 151.0.7922.72 allowed a remote attacker who had compromised the renderer process to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical weakness in Google Chrome's input validation mechanisms that could be exploited by attackers who have already gained access to the renderer process through prior compromises. The flaw specifically affects how Chrome handles password-related inputs and enables malicious actors to manipulate user interface elements through carefully crafted HTML content, potentially leading to confusion and deception of end users during authentication processes. The vulnerability stems from inadequate sanitization and validation of untrusted input data that flows through the browser's password handling components, creating an attack surface where malicious HTML can influence UI behavior without proper authorization checks.
The technical implementation of this vulnerability demonstrates a failure in Chrome's security model where renderer process isolation is bypassed through improper input validation. When a compromised renderer process encounters specially crafted HTML content containing malicious password-related elements, the browser fails to properly validate these inputs before rendering them to users. This creates opportunities for UI spoofing attacks where attackers can manipulate displayed password fields, authentication prompts, or related interface components to mislead users about their actual actions or the security status of their connections. The vulnerability operates at the intersection of input validation and user interface rendering, leveraging the trust model that exists within Chrome's architecture between renderer processes and the main browser UI components.
From an operational impact perspective, this vulnerability significantly weakens Chrome's defense-in-depth strategy for protecting users during authentication flows. Attackers who have already compromised a renderer process through other means can leverage this weakness to escalate their compromise by deceiving users into entering credentials or performing actions on manipulated interfaces. The medium severity classification reflects the fact that exploitation requires prior access to the renderer process, but once achieved, it provides attackers with capabilities that can undermine user trust and potentially lead to credential theft or unauthorized system access. This vulnerability particularly affects scenarios where users interact with untrusted websites or content that may be compromised through supply chain attacks or other initial compromise vectors.
The attack surface for this vulnerability aligns with several cybersecurity frameworks including CWE-20, which addresses "Improper Input Validation," and maps to ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript" as attackers would likely use JavaScript within the crafted HTML to manipulate UI elements. The vulnerability also relates to CWE-601, "URL Redirection to Untrusted Site After a Prompt," as it enables attackers to create deceptive user interfaces that may mislead users about their actual location or authentication status. Organizations should implement immediate mitigation strategies including updating Chrome to version 151.0.7922.72 or later, monitoring for suspicious renderer process behavior, and conducting security awareness training to help users recognize potential UI spoofing attempts.
Mitigation efforts should focus on both immediate patch deployment and enhanced monitoring of browser processes for unusual behavior patterns that might indicate exploitation attempts. Security teams should establish baseline behaviors for legitimate renderer processes and implement anomaly detection systems that can identify when password-related UI elements are being manipulated in ways that deviate from normal Chrome operation. Network security controls including web application firewalls and content filtering systems can help reduce the risk of initial compromise that leads to exploitation of this vulnerability, while endpoint detection and response solutions should monitor for suspicious JavaScript execution patterns that might indicate attempts to manipulate UI elements through malicious HTML content. The vulnerability serves as a reminder of the importance of robust input validation at multiple layers of browser security architecture and demonstrates how weaknesses in one component can create opportunities for broader compromise through user interface manipulation attacks.