CVE-2026-11277: Google Chrome Auth Bypass Vulnerability

CVE-2026-11277 Overview

CVE-2026-11277 affects Google Chrome for iOS versions prior to 149.0.7827.53. The vulnerability stems from insufficient policy enforcement that allows a remote attacker to bypass discretionary access control through a crafted HTML page. The flaw is categorized under [CWE-284] Improper Access Control and requires user interaction to trigger.

Google classified the underlying Chromium security severity as Low. The issue impacts the iOS build of Chrome specifically, which uses Apple's WebKit engine while inheriting Chrome's policy and access-control logic.

Critical Impact

A remote attacker can serve a crafted HTML page that bypasses Chrome for iOS access control enforcement, leading to limited integrity impact without compromising confidentiality or availability.

Affected Products

• Google Chrome for iOS versions prior to 149.0.7827.53
• Apple iPhone OS (as the underlying platform hosting the vulnerable Chrome build)
• Any iOS device running an outdated Chrome browser application

Discovery Timeline

• 2026-06-05 - CVE-2026-11277 published to the National Vulnerability Database
• 2026-06-09 - Last updated in NVD database

Technical Details for CVE-2026-11277

Vulnerability Analysis

The vulnerability resides in Chrome for iOS policy enforcement logic. Chrome maintains discretionary access controls that govern how web content interacts with browser-managed resources and platform boundaries. Insufficient enforcement of these policies allows a remote web page to perform actions normally prohibited by browser security policy.

Exploitation requires the victim to load attacker-controlled HTML content. Once loaded, the crafted page interacts with Chrome's policy enforcement boundary in a manner that the browser fails to block. The result is a discretionary access control bypass with limited integrity impact, as reflected by the I:L component of the CVSS vector.

Neither confidentiality nor availability is directly affected. The narrow scope reflects iOS sandboxing constraints, which limit what a bypass within Chrome can achieve at the operating system level. See the Chromium Issue Tracker Entry for additional technical context.

Root Cause

The root cause is improper access control [CWE-284] within Chrome for iOS. Policy checks fail to consistently apply discretionary access rules when processing specific HTML structures, allowing the rendering pipeline to act on content that should be restricted.

Attack Vector

The attack vector is network-based. An attacker hosts a malicious HTML page on a controlled domain or injects content into a compromised site. A user running a vulnerable Chrome for iOS build must visit the page for exploitation to succeed. No authentication is required, but user interaction is mandatory.

No public proof-of-concept code or exploit module has been published for this issue. The vulnerability is described in prose only by the upstream advisory. Refer to the Google Chrome Stable Update for vendor details.

Detection Methods for CVE-2026-11277

Indicators of Compromise

• Chrome for iOS clients reporting User-Agent strings with versions below 149.0.7827.53 in web server access logs
• Outbound connections from iOS devices to newly registered or low-reputation domains serving HTML pages with anomalous script structures
• Unexpected navigation chains or redirects originating from Chrome on iOS to attacker-controlled infrastructure

Detection Strategies

• Inventory managed iOS devices and query Chrome version metadata through mobile device management (MDM) telemetry to surface vulnerable installs
• Inspect web proxy and DNS logs for iOS Chrome clients visiting URLs flagged by threat intelligence feeds
• Correlate browser version data with phishing campaign indicators to prioritize at-risk users

Monitoring Recommendations

• Enable MDM-based browser version reporting and alert when Chrome for iOS builds fall below 149.0.7827.53
• Monitor for high-volume access from mobile clients to recently created HTML-only domains
• Track user reports of unexpected browser behavior, prompts, or content rendering anomalies on iOS

How to Mitigate CVE-2026-11277

Immediate Actions Required

• Update Google Chrome for iOS to version 149.0.7827.53 or later through the Apple App Store
• Enforce a minimum Chrome version policy on managed iOS fleets using MDM configuration profiles
• Communicate the update requirement to end users and verify compliance through device posture reporting

Patch Information

Google released the fix in Chrome for iOS 149.0.7827.53. Users should install the latest version directly from the Apple App Store. Enterprise administrators can review the Google Chrome Stable Update announcement and the Chromium Issue Tracker Entry for release context.

Workarounds

• Restrict use of Chrome for iOS on managed devices until the update is applied, directing users to a patched alternative browser
• Apply web filtering and DNS reputation controls to block access to known malicious domains hosting crafted HTML
• Educate users to avoid following untrusted links on mobile devices and to report unexpected browser behavior

# Verify Chrome for iOS version compliance via MDM query
# Required minimum version: 149.0.7827.53
mdm query --app com.google.chrome.ios --field CFBundleShortVersionString