CVE-2026-11264: Google Chrome CSP Bypass Vulnerability

CVE-2026-11264 Overview

CVE-2026-11264 is a Content Security Policy (CSP) bypass vulnerability in Google Chrome versions prior to 149.0.7827.53. The flaw allows a remote attacker to circumvent CSP protections through a crafted HTML page. Chromium classified the security severity as Low, while NVD assigned a medium rating. Exploitation requires user interaction, such as visiting an attacker-controlled page.

The vulnerability is tracked under CWE-693: Protection Mechanism Failure. Affected platforms include Chrome desktop builds on Windows, macOS, and Linux. Google addressed the issue in the stable channel update released in June 2026.

Critical Impact
A successful bypass undermines a primary browser defense against cross-site scripting and content injection, enabling attackers to execute restricted content within a victim's browsing context.

Affected Products

Google Chrome versions prior to 149.0.7827.53
Chrome on Microsoft Windows, Apple macOS, and Linux desktop builds
Chromium-based browsers and embedded WebView components inheriting the vulnerable CSP enforcement code

Discovery Timeline

2026-06-05 - CVE-2026-11264 published to the National Vulnerability Database
2026-06-08 - Last updated in NVD database

Technical Details for CVE-2026-11264

Vulnerability Analysis

The vulnerability resides in Chrome's Content Security Policy enforcement logic. CSP is a browser security mechanism that restricts which scripts, styles, frames, and other resources a web page may load or execute. A bypass means an attacker can deliver content that should be blocked by a site's declared policy, defeating a layered defense intended to mitigate cross-site scripting and data injection attacks.

The defect is categorized as a Protection Mechanism Failure [CWE-693]. Exploitation requires the victim to load a crafted HTML page, so the attack vector is network-based with required user interaction. The integrity impact is limited and the issue does not directly compromise confidentiality or availability of the host. Chromium engineers tracked the underlying defect in the Chromium Issue Tracker entry 500099106.

Root Cause

The root cause is an inconsistency in how Chrome's CSP module evaluates directives against specific HTML constructs. When the policy parser or enforcement layer mishandles a particular page structure, restricted content can be processed as if permitted. Public technical detail remains limited because Chromium restricts access to bug entries until users upgrade.

Attack Vector

An attacker hosts a crafted HTML page and lures a target user to visit it through phishing, malvertising, or a compromised site. When the page renders in a vulnerable Chrome build, the CSP enforcement gap allows content that the target site's policy would otherwise block. This can facilitate downstream attacks such as script execution or exfiltration when chained with a site-level injection flaw.

No public proof-of-concept, exploit module, or CISA Known Exploited Vulnerabilities listing exists for this CVE at the time of publication. The EPSS probability is 0.029%, indicating low predicted exploitation activity.

Detection Methods for CVE-2026-11264

Indicators of Compromise

Browser telemetry showing execution of inline scripts or remote resources on sites that declare a restrictive Content-Security-Policy header
Outbound connections from browser processes to domains not listed in connect-src, script-src, or frame-src directives of visited sites
User reports of unexpected redirects or content rendering after visiting unfamiliar HTML pages

Detection Strategies

Inventory installed Chrome versions across managed endpoints and flag any build earlier than 149.0.7827.53
Monitor web proxy and DNS logs for visits to newly registered domains delivering HTML that targets browser policy weaknesses
Correlate browser process telemetry with CSP violation reports collected via report-uri or report-to endpoints on internally hosted applications

Monitoring Recommendations

Enable CSP reporting on internal web applications and forward reports to a centralized log store for analysis
Track Chrome update compliance using endpoint management tooling and alert on drift from the patched baseline
Review browser extension activity, since malicious extensions can amplify the impact of a CSP bypass

How to Mitigate CVE-2026-11264

Immediate Actions Required

Update Google Chrome to version 149.0.7827.53 or later on all Windows, macOS, and Linux endpoints
Restart browser sessions after deployment to ensure the patched binary is loaded into memory
Audit Chromium-based browsers and embedded WebView frameworks for equivalent updates from their respective vendors

Patch Information

Google released the fix in the stable channel update documented in the Chrome Releases blog for June 2026. Administrators should deploy version 149.0.7827.53 or later through enterprise update mechanisms such as Chrome Browser Cloud Management, Group Policy, or platform-native package managers.

Workarounds

Restrict browsing to trusted sites using URL filtering or secure web gateways until patches are deployed
Apply defense-in-depth on owned web applications by combining CSP with X-Content-Type-Options, X-Frame-Options, and strict input validation
Disable or remove unnecessary browser extensions that could broaden the impact of a CSP bypass

bash

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

# Verify installed Chrome version on macOS
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version

# Verify installed Chrome version on Windows (PowerShell)
(Get-Item "$env:ProgramFiles\Google\Chrome\Application\chrome.exe").VersionInfo.ProductVersion