CVE-2026-11026: Chrome Extension Navigation Bypass Vulnerability

Technical summary

CVE-2026-11026 stems from an inappropriate implementation in Chrome's extension system that fails to properly enforce navigation restrictions. The vulnerability is triggered when a user installs a malicious extension crafted to exploit this weakness. The flaw allows the extension to bypass Chrome's navigation control mechanisms, which are designed to prevent unauthorized redirection and enforce security policies. The attack vector is network-based with low attack complexity; however, user interaction is required both to install the extension and potentially to trigger the bypass. The vulnerability maps to CWE-284 (Improper Access Control), reflecting the core issue of insufficient enforcement of security boundaries within the extension framework.

Business impact

Organizations should be concerned about this vulnerability in their workforce Chrome deployments, particularly in settings where users may be encouraged to install extensions from untrusted sources or where social engineering is plausible. A successful attack could redirect employees to phishing sites, malware distribution points, or credential harvest pages, undermining user trust in the browser's navigation security. The requirement for prior malicious extension installation limits the immediate blast radius, but the impact on compromised users could include credential theft, malware infection, or unauthorized access to sensitive web applications. Remediation requires user awareness training alongside timely patching.

Affected systems

Google Chrome on Windows, macOS, and Linux systems running versions prior to 149.0.7827.53 are affected. The vulnerability impacts all three major operating systems, making it broadly relevant to cross-platform environments. Linux kernel, Windows, and macOS are listed as affected platforms, indicating the issue is inherent to Chrome's extension handling rather than OS-specific. Organizations maintaining Chrome across multiple operating systems should prioritize uniform patch deployment.

Exploitability

Exploitability is limited by the social engineering requirement: an attacker must first convince a user to install a malicious extension. This is not a one-click or automatic compromise vector. Once an extension is installed, however, the bypass itself is likely reliable given the inappropriate implementation in Chrome's extension system. The CVSS vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N) reflects network accessibility, low attack complexity for the bypass mechanism itself, and high integrity impact. The attack does not appear in the CISA KEV catalog, suggesting limited evidence of active exploitation in the wild at the time of analysis, though this should be monitored.

Remediation

Update Google Chrome to version 149.0.7827.53 or later. This patch addresses the inappropriate extension implementation and restores proper navigation restriction enforcement. Patch availability should be verified against the official Google Chrome release notes and your organization's patch management system. Concurrent user education is essential: remind staff not to install extensions from untrusted sources, to review extension permissions carefully before installation, and to report suspicious extension behavior.

Patch guidance

Deploy Chrome 149.0.7827.53 or newer across your fleet using your organization's standard patch management process. For managed Chrome deployments (via Chrome Enterprise or similar), ensure managed policies are updated to enforce the minimum version requirement. Verify patch deployment by checking the Chrome version in Settings > About Chrome, which will auto-update once the patch is available. Monitor for any extension-related incidents in your security logs post-patch to detect any residual exposure from previously installed malicious extensions. Consider also reviewing extension policy settings in your environment to restrict installation to approved catalogs only.

Detection guidance

Monitor for unusual extension installations, particularly from unknown sources or with atypical permissions. Inspect Chrome's extension list (chrome://extensions/) on high-risk systems for any extensions requesting navigation-related permissions that are not business-justified. Review browser console logs and network traffic for unexpected redirects originating from extension activity. Endpoint Detection and Response (EDR) solutions should flag suspicious extension processes or inter-process communication. For managed deployments, audit extension manifests for indicators of manipulation or obfuscation. DNS and web gateway logs may capture redirect anomalies if the bypass is leveraged for phishing or malware distribution.

Why prioritize this

Prioritize this patch based on user-facing risk and social engineering likelihood in your environment. While the CVSS score of 6.5 is moderate, the integrity impact (high) combined with the potential for credential theft or malware distribution justifies prompt deployment. The lack of KEV status suggests active exploitation is not widespread, but proactive patching limits risk surface. Organizations with strong user awareness programs may delay slightly; those with less mature security culture should expedite. The attack chain (install malicious extension → trigger bypass → redirect user) is plausible enough to warrant treatment as a high-priority patch within normal patch cycles.

Risk score, explained

The CVSS 6.5 (Medium) score reflects the confluence of network-based delivery, low attack complexity for the bypass itself, but mandatory user interaction for extension installation. Integrity is marked as high because successful exploitation enables redirection attacks that could compromise data confidentiality or system availability downstream. Confidentiality and availability are not directly impacted by the navigation bypass itself, which explains why those vectors are marked as None. The score appropriately captures that this is not a trivial vulnerability, but also not a critical remote code execution—it is a stepping stone in a social engineering attack chain.

Frequently asked questions