CVE-2026-5890: Google Chrome Information Disclosure Flaw

CVE-2026-5890 Overview

A race condition vulnerability exists in the WebCodecs component of Google Chrome prior to version 147.0.7727.55. This flaw allows a remote attacker to obtain potentially sensitive information from process memory by exploiting a timing-related issue through a crafted HTML page. The vulnerability is classified under CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), commonly known as a race condition.

Critical Impact

Remote attackers can exploit this race condition to leak sensitive process memory contents, potentially exposing confidential data, session tokens, or other security-critical information stored in Chrome's memory space.

Affected Products

• Google Chrome versions prior to 147.0.7727.55
• Chromium-based browsers using affected WebCodecs implementation

Discovery Timeline

• 2026-04-08 - CVE CVE-2026-5890 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-5890

Vulnerability Analysis

This vulnerability stems from a race condition in Google Chrome's WebCodecs API implementation. WebCodecs is a browser API that provides low-level access to individual frames of video streams and chunks of audio, enabling web applications to perform advanced media processing tasks.

The race condition occurs when concurrent threads or processes access shared resources within the WebCodecs component without proper synchronization. When an attacker crafts a malicious HTML page that deliberately triggers specific timing conditions, the browser can enter an inconsistent state where memory contents that should be protected become accessible.

Race conditions in browser contexts are particularly dangerous because they can be triggered remotely simply by visiting a malicious webpage. The attacker does not require any special privileges or user interaction beyond the initial page load.

Root Cause

The root cause of CVE-2026-5890 is improper synchronization in the WebCodecs implementation. When multiple operations attempt to access or modify shared data structures simultaneously, the lack of proper locking mechanisms or atomic operations creates a window where an attacker can read process memory in an unintended state. This Time-of-Check to Time-of-Use (TOCTOU) scenario allows memory contents to be extracted before security checks are properly applied.

Attack Vector

The attack vector for this vulnerability involves serving a specially crafted HTML page to a victim. The malicious page contains JavaScript code that interacts with the WebCodecs API in a manner designed to trigger the race condition. By carefully timing API calls and exploiting the synchronization gap, an attacker can cause the browser to leak sensitive information from process memory.

The attack is particularly concerning because it requires minimal user interaction—simply navigating to a malicious website is sufficient to trigger the vulnerability. No additional permissions, downloads, or clicks are required, making this an effective vector for information disclosure attacks.

Detection Methods for CVE-2026-5890

Indicators of Compromise

• Unexpected memory access patterns in Chrome browser processes
• Unusual WebCodecs API usage in browser developer tools or logs
• JavaScript payloads making rapid, repeated calls to WebCodecs interfaces
• Browser crashes or instability following visits to suspicious websites

Detection Strategies

• Monitor for abnormal WebCodecs API call patterns that may indicate exploitation attempts
• Deploy browser isolation solutions to contain potential memory disclosure attacks
• Implement network-level detection for known malicious HTML patterns targeting WebCodecs
• Use endpoint detection tools to identify unusual Chrome process behavior

Monitoring Recommendations

• Enable enhanced browser logging to capture WebCodecs API interactions
• Monitor for Chrome crash dumps that may indicate exploitation attempts
• Review web traffic logs for access to domains known to host browser exploits
• Implement browser telemetry to detect anomalous memory consumption patterns

How to Mitigate CVE-2026-5890

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.55 or later immediately
• Enable automatic browser updates to ensure timely security patches
• Consider temporarily disabling WebCodecs API via Chrome flags if immediate patching is not possible
• Implement browser isolation for high-risk users or environments

Patch Information

Google has addressed this vulnerability in Chrome version 147.0.7727.55. The fix implements proper synchronization mechanisms in the WebCodecs component to prevent the race condition from being exploited. Organizations should prioritize updating all Chrome installations to the patched version.

For additional details, refer to the Google Chrome Update Announcement and the Chromium Issue Tracker Entry.

Workarounds

• Disable WebCodecs API functionality via Chrome enterprise policies until patching is complete
• Use site isolation features to limit cross-origin memory access
• Implement content security policies to restrict JavaScript execution from untrusted sources
• Deploy web filtering to block access to known malicious domains exploiting this vulnerability

# Chrome enterprise policy to restrict WebCodecs (temporary workaround)
# Add to Chrome policies configuration
chrome --disable-features=WebCodecs

# Or via enterprise policy JSON:
# {
#   "WebCodecsEnabled": false
# }