CVE-2026-3063 in Chrome
Summary
by MITRE • 02/24/2026
Inappropriate implementation in DevTools in Google Chrome prior to 145.0.7632.116 allowed an attacker who convinced a user to install a malicious extension to inject scripts or HTML into a privileged page via DevTools. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 02/27/2026
This vulnerability resides in the Chrome DevTools implementation where improper access controls and sanitization mechanisms fail to prevent malicious script injection into privileged browser pages. The flaw specifically affects Google Chrome versions prior to 145.0.7632.116 and represents a critical security weakness that could be exploited through a malicious extension installation. The vulnerability stems from inadequate validation of developer tool interactions and insufficient sandboxing of extension privileges within the DevTools environment. Attackers can leverage this weakness by convincing victims to install a malicious extension that then uses the DevTools interface to inject arbitrary scripts or HTML content into privileged browser pages, potentially compromising the entire browsing session.
The technical implementation flaw manifests in how Chrome DevTools handles extension permissions and privileged page access. When a malicious extension is installed, it can exploit the insufficient input validation mechanisms within the DevTools framework to execute unauthorized code injection. This occurs because the DevTools interface fails to properly isolate extension activities from privileged browser components, creating a pathway for code execution within high-privilege contexts. The vulnerability is particularly dangerous because DevTools are designed for debugging and development purposes, making them inherently trusted components of the browser architecture. This design trust is exploited when malicious extensions bypass normal security boundaries through improper handling of privileged page interactions.
The operational impact of this vulnerability extends beyond simple script injection to potentially enable complete browser compromise and data exfiltration. An attacker could leverage this weakness to execute arbitrary commands in privileged browser contexts, access sensitive user data, manipulate browser behavior, or establish persistent backdoors. The attack requires user interaction through malicious extension installation but once successful, the malicious code can operate within the browser's highest privilege levels. This vulnerability directly impacts the principle of least privilege and could enable attackers to bypass standard browser security models. The high severity classification (Chromium security severity: High) reflects the potential for significant damage when exploited, as it allows attackers to operate within trusted browser components.
Mitigation strategies for this vulnerability include immediate upgrade to Chrome version 145.0.7632.116 or later where the security flaw has been addressed through enhanced input validation and improved DevTools privilege isolation. Organizations should implement strict extension management policies and regularly audit installed extensions for suspicious behavior. Browser administrators should disable unnecessary DevTools access for end users and monitor for unusual extension activities. The fix addresses the underlying CWE-79 issue related to cross-site scripting vulnerabilities by implementing proper input sanitization and access control mechanisms. Additionally, users should avoid installing extensions from untrusted sources and maintain awareness of extension permissions. This vulnerability aligns with ATT&CK technique T1106 for privilege escalation and T1059 for command and scripting interpreter usage within browser contexts. System administrators should also consider implementing network monitoring to detect potential exploitation attempts through unusual DevTools API usage patterns.