CVE-2026-7937: Google Chrome Auth Bypass Vulnerability

CVE-2026-7937 Overview

CVE-2026-7937 is an insufficient policy enforcement vulnerability in the DevTools component of Google Chrome prior to version 148.0.7778.96. An attacker who convinces a user to install a malicious Chrome extension can bypass navigation restrictions through a crafted extension. The flaw is tracked under [CWE-693: Protection Mechanism Failure] and was assigned a Chromium severity of Medium. Google addressed the issue in the Stable Channel update for desktop. Successful exploitation requires user interaction, specifically the installation of an attacker-controlled extension, which limits realistic attack scenarios to social engineering and supply chain compromise of legitimate extensions.

Critical Impact
Attackers leveraging a malicious extension can bypass DevTools navigation restrictions, expanding the reach of extension-based attacks against browser users.

Affected Products

Google Chrome prior to 148.0.7778.96 on Microsoft Windows
Google Chrome prior to 148.0.7778.96 on Apple macOS
Google Chrome prior to 148.0.7778.96 on Linux

Discovery Timeline

2026-05-06 - CVE-2026-7937 published to NVD
2026-05-06 - Last updated in NVD database
2026-05 - Google releases Stable Channel update for desktop addressing the issue

Technical Details for CVE-2026-7937

Vulnerability Analysis

The vulnerability resides in Chrome DevTools, the browser's built-in developer interface. DevTools enforces policies that restrict where extensions can navigate the browsing context. In affected versions, those policy checks are insufficient when invoked through specific Chrome Extension APIs. A crafted extension can issue navigation requests that DevTools fails to validate against the intended policy boundary. The result is a navigation restriction bypass that extends the privileges available to extension code beyond what the security model permits. The flaw maps to [CWE-693], reflecting a protection mechanism failure rather than a memory safety issue. Exploitation requires an attacker to convince a user to install a malicious extension, which is the primary mitigating factor that reduces the practical attack surface.

Root Cause

The root cause is incomplete enforcement of navigation policies within the DevTools code paths exposed to extensions. The check that should reject restricted navigations does not cover all extension-driven entry points, allowing a crafted extension manifest and accompanying scripts to reach navigation primitives that should be unreachable. Refer to Chromium Issue #491766258 for upstream tracking.

Attack Vector

The attack vector is network-based but requires user interaction. An attacker publishes or hijacks a Chrome extension and persuades a victim to install it. Once installed, the extension uses crafted DevTools interactions to bypass navigation restrictions, potentially redirecting users or accessing contexts the extension policy would normally block. The vulnerability does not require elevated privileges on the host system. Code-level details are not publicly disclosed. See the Google Chrome Stable Update advisory for vendor-supplied technical context.

Detection Methods for CVE-2026-7937

Indicators of Compromise

Installation of unverified or sideloaded Chrome extensions, especially those requesting debugger or DevTools-related permissions.
Extensions originating from outside the Chrome Web Store or recently transferred to new publishers.
Unexpected navigations or tab redirections that coincide with extension activity in browser telemetry.

Detection Strategies

Inventory installed Chrome extensions across managed endpoints and compare against an approved allowlist.
Monitor Chrome version strings reported by endpoints and flag any host running a build earlier than 148.0.7778.96.
Review extension manifests for debugger, webNavigation, and broad host permissions that could enable abuse of this class of bug.

Monitoring Recommendations

Forward browser process telemetry and extension installation events into a centralized analytics platform for correlation.
Alert on Chrome extension installations performed outside enterprise deployment channels.
Track outbound navigation patterns from browser processes to detect anomalous redirections following extension installation.

How to Mitigate CVE-2026-7937

Immediate Actions Required

Update Google Chrome to version 148.0.7778.96 or later on Windows, macOS, and Linux endpoints.
Audit installed extensions and remove any that are not explicitly approved for business use.
Communicate to users that they must not install Chrome extensions from untrusted sources or in response to unsolicited prompts.

Patch Information

Google released the fix in the Chrome Stable Channel update covering version 148.0.7778.96. Apply the update through the standard Chrome auto-update mechanism or enterprise deployment tooling. Details are available in the Google Chrome Stable Update announcement and the upstream Chromium Issue #491766258.

Workarounds

Enforce an enterprise extension allowlist using the ExtensionInstallAllowlist and ExtensionInstallBlocklist Chrome policies until patching completes.
Disable installation of extensions outside the Chrome Web Store via the ExtensionInstallSources policy.
Restrict DevTools availability for managed users with the DeveloperToolsAvailability policy where business workflows allow.

bash

# Example Chrome enterprise policy (Linux managed_policies JSON)
{
  "ExtensionInstallBlocklist": ["*"],
  "ExtensionInstallAllowlist": [
    "<approved-extension-id-1>",
    "<approved-extension-id-2>"
  ],
  "DeveloperToolsAvailability": 2
}