CVE-2026-11260: Google Chrome Auth Bypass Vulnerability

CVE-2026-11260 Overview

CVE-2026-11260 is a content security policy (CSP) bypass vulnerability in Google Chrome. The flaw stems from an inappropriate implementation in the Permissions component in Chrome versions prior to 149.0.7827.53. A remote attacker can exploit the weakness by serving a crafted HTML page, causing the browser to bypass CSP restrictions when a user visits the malicious site. Google classified the Chromium security severity as Low, and the issue is tracked under CWE-693: Protection Mechanism Failure. The vulnerability affects Chrome on Windows, macOS, and Linux. User interaction is required, and exploitation does not grant code execution but undermines a defensive control web applications rely on.

Critical Impact
A remote attacker can bypass content security policy enforcement via a crafted HTML page, weakening protections against script injection and data exfiltration on affected web origins.

Affected Products

Google Chrome versions prior to 149.0.7827.53
Chrome desktop on Microsoft Windows, Apple macOS, and Linux
Chromium-based browsers that incorporate the vulnerable Permissions implementation

Discovery Timeline

2026-06-05 - CVE-2026-11260 published to the National Vulnerability Database
2026-06-08 - Last updated in the NVD database
2026-06-05 - Google releases the Stable Channel Update for Desktop containing the fix

Technical Details for CVE-2026-11260

Vulnerability Analysis

The vulnerability resides in the Permissions component of Google Chrome and is categorized under CWE-693: Protection Mechanism Failure. The implementation does not correctly enforce content security policy directives in a specific permission-handling code path. As a result, a crafted HTML page can cause Chrome to skip or misapply CSP checks that would normally block disallowed content sources or inline behaviors.

The issue affects confidentiality and integrity only at a limited level. There is no memory corruption and no direct path to arbitrary code execution. The risk lies in the erosion of a defense-in-depth control that web applications use to mitigate cross-site scripting and data exfiltration. Sites that depend on strict CSP enforcement to contain attacker-controlled content lose part of that protection on vulnerable Chrome builds.

Root Cause

The root cause is an inappropriate implementation in the Permissions module. The component fails to consistently apply the document's content security policy when processing certain permission-related operations triggered by a crafted page. Google tracks the underlying defect as Chromium Issue 499257860.

Attack Vector

Exploitation is network-based and requires user interaction. An attacker hosts a crafted HTML page on a controlled origin and lures the victim to visit it, typically through phishing, malvertising, or a compromised site. When the page loads in a vulnerable Chrome build, it triggers the permission code path that bypasses CSP. The attacker can then load or execute content that the CSP would have otherwise blocked. Privileges are not required, and no prior authentication to the target site is needed.

No public proof-of-concept code, exploit module, or in-the-wild exploitation has been reported. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-11260

Indicators of Compromise

Chrome desktop clients reporting a version string below 149.0.7827.53 in browser telemetry or asset inventories.
Web server logs showing requests from older Chrome user agents to pages that subsequently trigger unexpected outbound connections to attacker-controlled domains.
CSP violation report endpoints showing an unexplained drop in expected violations from older Chrome builds, suggesting checks were bypassed.

Detection Strategies

Inventory installed Chrome versions across managed endpoints and flag any host running a build older than 149.0.7827.53.
Correlate browser version data with web proxy logs to identify users visiting untrusted external sites while running vulnerable builds.
Monitor CSP report-uri and report-to endpoints for anomalies that may indicate inconsistent policy enforcement.

Monitoring Recommendations

Ingest endpoint browser version telemetry into a centralized data lake and alert on out-of-date Chrome installations.
Track Chromium security release notes and map advisories to internal patch SLAs for browsers and Electron-based applications.
Review web application CSP reports weekly to detect enforcement gaps tied to specific browser versions.

How to Mitigate CVE-2026-11260

Immediate Actions Required

Update Google Chrome on Windows, macOS, and Linux to version 149.0.7827.53 or later on all managed endpoints.
Force a browser restart after the update so the patched binary is loaded into running sessions.
Audit Chromium-based applications and embedded browser frameworks for the same vulnerable code path and update them when vendor patches are available.

Patch Information

Google addressed CVE-2026-11260 in the Stable Channel Update for Desktop. The fix ships in Chrome 149.0.7827.53 and later. Patch details are documented in the Google Chrome Stable Update advisory, and the underlying defect is tracked in Chromium Issue #499257860.

Workarounds

Restrict browsing to trusted sites using enterprise URL allowlists until patching is complete.
Disable or limit access to high-risk sites in web proxies and DNS filtering platforms to reduce exposure to crafted HTML pages.
Enforce strict CSP policies server-side with additional controls such as Subresource Integrity and Trusted Types so a single bypass does not eliminate all protections.

bash

# Verify Chrome version on Linux endpoints
google-chrome --version

# Windows: query installed Chrome version via registry
reg query "HKLM\Software\Google\Update\Clients\{8A69D345-D564-463C-AFF1-A69D9E530F96}" /v pv

# macOS: read the bundle version
defaults read /Applications/Google\ Chrome.app/Contents/Info CFBundleShortVersionString