CVE-2026-11197 in Chrome
Summary
by MITRE • 06/05/2026
Insufficient policy enforcement in Workers in Google Chrome prior to 149.0.7827.53 allowed a remote attacker who had compromised the renderer process to bypass same origin policy via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 06/05/2026
This vulnerability represents a critical weakness in Google Chrome's cross-origin resource sharing mechanisms within the Workers component, specifically affecting versions prior to 149.0.7827.53. The issue stems from insufficient policy enforcement that allows a remote attacker with compromised renderer process access to bypass the fundamental same origin policy protections that govern web browser security. The same origin policy serves as a cornerstone of web security by preventing scripts from one origin from accessing resources from another origin without proper authorization, and its compromise creates significant attack surface for malicious actors. This vulnerability is classified as a medium severity issue by Chromium security standards, indicating the potential for serious security implications when exploited.
The technical flaw manifests in how Chrome Workers handle cross-origin requests and policy enforcement, particularly when an attacker has already gained control of the renderer process through a separate exploitation vector. Workers in web browsers are designed to run scripts in background threads, but the insufficient policy enforcement means that these background processes fail to properly validate cross-origin access requests. When a compromised renderer process executes malicious code, it can leverage this vulnerability to make unauthorized cross-origin requests that would normally be blocked by the same origin policy. This bypass allows attackers to potentially access sensitive data or resources that should be restricted to the same origin, effectively undermining the browser's security model. The vulnerability is categorized under CWE-284, which deals with insufficient access control mechanisms, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1566 for credential harvesting through social engineering.
The operational impact of this vulnerability extends beyond simple data access, as it enables attackers to perform cross-origin information leakage and potentially escalate their privileges within the browser environment. Once an attacker has compromised the renderer process, they can use this vulnerability to access resources from different origins that would normally be protected, potentially leading to data exfiltration, session hijacking, or further exploitation of other browser components. The attack requires an initial compromise of the renderer process, which typically occurs through other vulnerabilities such as memory corruption issues, sandbox escapes, or privilege escalation flaws, making this vulnerability particularly dangerous when combined with other exploits. Organizations and users face increased risk of targeted attacks where attackers first compromise the renderer process and then leverage this Workers vulnerability to expand their access within the browser environment.
Mitigation strategies for this vulnerability require immediate patching to Chrome versions 149.0.7827.53 and later, which contain the necessary fixes to properly enforce same origin policy within Workers. System administrators should prioritize updating Chrome installations across all affected systems, particularly in enterprise environments where the risk of targeted attacks is higher. Additional defensive measures include implementing strict content security policies that limit cross-origin requests, monitoring for unusual Worker activity patterns, and maintaining up-to-date browser security configurations. The vulnerability highlights the importance of comprehensive security testing for browser components, particularly those that handle cross-origin operations, and underscores the need for robust policy enforcement mechanisms throughout the browser architecture. Organizations should also consider implementing network monitoring solutions to detect potential exploitation attempts and ensure that all browser updates are deployed promptly to protect against known vulnerabilities.