CVE-2026-11212 in Chrome
Summary
by MITRE • 06/05/2026
Insufficient policy enforcement in DevTools in Google Chrome prior to 149.0.7827.53 allowed an attacker who convinced a user to install a malicious extension to leak cross-origin data via a crafted Chrome Extension. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 06/06/2026
This vulnerability represents a critical flaw in Chrome's DevTools implementation that undermines the browser's security model through inadequate policy enforcement mechanisms. The issue stems from insufficient validation of extension permissions and cross-origin data access controls within the debugging interface, creating a pathway for malicious actors to exploit user trust and bypass security boundaries. The vulnerability affects Chrome versions prior to 149.0.7827.53 and specifically targets the DevTools extension infrastructure that should enforce strict isolation between different origins and extension contexts. Attackers could craft malicious extensions that leverage the DevTools interface to access and exfiltrate sensitive data from cross-origin resources, effectively circumventing the same-origin policy that forms the cornerstone of web security.
The technical implementation flaw resides in how Chrome's DevTools handles extension installation and execution contexts, where the security boundaries between different origins become blurred during debugging sessions. When users install malicious extensions through the DevTools interface, the system fails to properly validate the extension's intent and capabilities, allowing extensions to request elevated privileges that should be restricted. This weakness creates an attack surface where a malicious extension can leverage the debugging interface to access cross-origin data that would normally be protected by browser security mechanisms. The vulnerability operates through a combination of improper access control checks and insufficient sandboxing within the DevTools environment, enabling extensions to escalate privileges and access resources they should not be permitted to access.
The operational impact of this vulnerability extends beyond simple data leakage, as it represents a fundamental breakdown in Chrome's extension security model that could enable more sophisticated attacks. An attacker could use this vulnerability to perform reconnaissance across different origins, gather sensitive information from multiple websites, and potentially establish persistent access patterns through the DevTools interface. The medium severity classification reflects the fact that exploitation requires user interaction through extension installation, but once successful, the impact can be significant for users who trust the DevTools environment. This vulnerability directly impacts the integrity of Chrome's security model and could enable attackers to bypass protections that are essential for maintaining user privacy and data security across different web applications.
Organizations and users should prioritize updating to Chrome version 149.0.7827.53 or later to address this vulnerability, as the fix implements enhanced policy enforcement mechanisms that properly validate extension permissions and cross-origin access requests. The mitigation strategy should include regular browser updates, careful review of extension permissions before installation, and monitoring for suspicious DevTools activity. Security teams should also consider implementing network-level monitoring to detect unusual cross-origin data access patterns that could indicate exploitation attempts. This vulnerability aligns with CWE-284 (Improper Access Control) and maps to ATT&CK techniques related to privilege escalation and credential access through browser-based attacks. The fix demonstrates the importance of maintaining strict security boundaries within browser debugging interfaces and reinforces the need for comprehensive policy enforcement mechanisms that prevent unauthorized access to cross-origin resources.