CVE-2026-15768: Google Chrome Auth Bypass Vulnerability

CVE-2026-15768 Overview

CVE-2026-15768 is a same-origin policy (SOP) bypass vulnerability in the HTML-in-Canvas feature of Google Chrome. Versions prior to 150.0.7871.125 fail to enforce origin policy checks when rendering HTML content inside a <canvas> element. A remote attacker can exploit the flaw by serving a crafted HTML page that a user visits. The issue is tracked under CWE-346: Origin Validation Error and Chromium classifies its internal severity as High.

Critical Impact
An attacker-controlled page can read cross-origin content that the SOP is designed to isolate, exposing authenticated data from unrelated sites loaded in the same browser session.

Affected Products

Google Chrome for Desktop prior to 150.0.7871.125
Chromium-based browsers that embed the affected HTML-in-Canvas implementation
Applications relying on Chromium's Blink rendering engine before the July 2026 stable channel update

Discovery Timeline

2026-07-14 - CVE-2026-15768 published to NVD
2026-07-15 - Last updated in NVD database

Technical Details for CVE-2026-15768

Vulnerability Analysis

The HTML-in-Canvas feature allows web developers to draw live HTML content into a <canvas> element, blending DOM rendering with the 2D graphics context. Chrome must enforce the same-origin policy on this path so that pixel data from cross-origin frames cannot be read back through canvas APIs such as getImageData() or toDataURL().

In versions prior to 150.0.7871.125, the origin check on the HTML-in-Canvas pipeline is insufficient. A crafted HTML page can cause cross-origin content to be composited into a canvas whose bitmap remains readable by the attacker's script. The confidentiality impact is high, while integrity and availability are unaffected, matching the observed exploitation profile of SOP bypasses.

Root Cause

The root cause is an origin validation error [CWE-346] in the HTML-in-Canvas rendering path. The code does not consistently mark the canvas as origin-tainted when cross-origin HTML is drawn into it. As a result, subsequent reads from the canvas bypass the browser's cross-origin read blocking.

Attack Vector

Exploitation requires user interaction, typically visiting a malicious or compromised web page. The attacker hosts HTML that instructs Chrome to render targeted cross-origin content into a canvas, then extracts pixel data or serialized representations of that content. No privileges are required and the attack is delivered entirely over the network. Refer to the Chromium Issue Tracker Entry for further technical detail.

No public proof-of-concept has been released and the flaw is not listed in the CISA Known Exploited Vulnerabilities catalog. The EPSS probability is 0.208%.

Detection Methods for CVE-2026-15768

Indicators of Compromise

Chrome browsers reporting a version string below 150.0.7871.125 in chrome://version or endpoint inventory telemetry
Outbound web requests to attacker-controlled pages that load authenticated third-party origins into hidden iframes or canvases
Unexpected large POST uploads containing base64-encoded image data shortly after users visit unfamiliar sites

Detection Strategies

Query endpoint management data for Chrome installations that have not received the 150.0.7871.125 stable channel update
Correlate browser process telemetry with DNS or proxy logs to identify visits to newly registered or low-reputation domains hosting canvas-heavy content
Review web proxy logs for data: URI exfiltration patterns and long base64 payloads returned to third-party endpoints

Monitoring Recommendations

Track Chrome version drift across managed endpoints and alert when hosts remain on vulnerable builds beyond the patch window
Monitor for anomalous access to sensitive internal web applications from browser sessions that also loaded external untrusted origins
Ingest browser and proxy telemetry into a centralized data lake to enable retrospective hunting once new indicators emerge

How to Mitigate CVE-2026-15768

Immediate Actions Required

Update Google Chrome to version 150.0.7871.125 or later on all managed endpoints
Restart Chrome after the update to ensure the patched renderer is loaded into every browser process
Force reevaluation of Chromium-based browsers and embedded WebView components to confirm they consume the fixed Blink release

Patch Information

Google addressed the flaw in the stable channel release announced in the Google Chrome Update Announcement. The fix ships in Chrome 150.0.7871.125 for desktop platforms. Enterprises using managed update policies should verify that the auto-update mechanism is not blocked by group policy or network egress restrictions.

Workarounds

Restrict browsing to trusted origins through enterprise web filtering until patches are deployed
Disable experimental HTML-in-Canvas features via chrome://flags where operationally feasible
Segment sensitive internal web applications from general browsing profiles using separate Chrome user profiles or containerized browsers

bash

# Verify Chrome version on Linux endpoints and flag hosts below the patched build
google-chrome --version | awk '{print $3}' | \
  awk -F. '{ if ($1 < 150 || ($1==150 && $2==0 && $3 < 7871) || \
              ($1==150 && $2==0 && $3==7871 && $4 < 125)) \
              print "VULNERABLE: " $0; else print "PATCHED: " $0 }'