CVE-2026-17927 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient policy enforcement in DevTools in Google Chrome prior to 151.0.7922.72 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: Low)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical weakness in Chrome's DevTools implementation that stems from inadequate policy enforcement mechanisms governing extension permissions and cross-origin data access. The flaw existed in Google Chrome versions prior to 151.0.7922.72 and specifically targeted the developer tools interface where malicious extensions could exploit insufficient sandboxing controls to bypass normal security boundaries. The vulnerability operates through a sophisticated attack vector where an adversary must first convince a victim to install a crafted malicious extension, which then leverages the DevTools environment to access data from different origins that should normally be restricted. This represents a classic case of privilege escalation through social engineering combined with browser-level security bypass techniques.
The technical implementation of this vulnerability exploits the trust model between Chrome's DevTools interface and installed extensions, where certain debugging capabilities were not properly segregated from standard extension permissions. Attackers could craft malicious extensions that, when loaded into Chrome's DevTools environment, gained access to cross-origin resources that should have been protected by the browser's same-origin policy enforcement mechanisms. The vulnerability specifically enabled unauthorized data exfiltration through the extension's ability to interact with debugging APIs that were not properly constrained by origin-based security policies. This weakness falls under the category of insufficient enforcement of security policies as defined by CWE-693, which addresses inadequate implementation of security controls that should prevent unauthorized access to protected resources.
The operational impact of this vulnerability extends beyond simple data leakage, as it provides attackers with a persistent mechanism for cross-origin information gathering and potential reconnaissance activities. Once installed, the malicious extension could monitor and exfiltrate sensitive data from multiple domains visited by the user, effectively creating a surveillance capability that bypassed traditional web security boundaries. The low severity classification from Chromium's security team belies the actual risk level, as this vulnerability could be weaponized to create sophisticated tracking mechanisms or serve as a foundation for more advanced attacks. The attack requires minimal user interaction beyond extension installation, making it particularly dangerous in environments where users might encounter malicious extensions through various distribution channels.
Mitigation strategies should focus on immediate browser updates to version 151.0.7922.72 or later, which contain the necessary security patches addressing the DevTools policy enforcement gaps. Organizations should implement strict extension installation policies and regularly audit installed extensions within their Chrome environments. The vulnerability highlights the importance of maintaining up-to-date browser versions as recommended by the ATT&CK framework's defensive techniques for maintaining defenses against browser-based attacks. Additional protective measures include implementing content security policies that restrict cross-origin resource access, using Chrome's built-in extension management features, and monitoring for suspicious DevTools activity through network traffic analysis. Regular security assessments should verify that no malicious extensions have been installed, particularly those that might exploit the debugging interfaces to bypass normal security controls.