CVE-2026-78915 Overview
CVE-2026-78915 is a race condition [CWE-362] in the Enterprise component of Google Chrome on Windows. The flaw affects versions prior to 152.0.7977.65 and allows an adjacent-network attacker to potentially execute arbitrary code outside the Chrome sandbox through crafted network traffic. Google's Chromium team rated the Chromium security severity as Low, while the NVD assigns a higher score reflecting the sandbox-escape impact.
Critical Impact
An attacker on the same logical network segment can trigger the race condition with crafted traffic to escape the Chrome sandbox and execute code in a higher-privileged renderer or broker context on Windows hosts.
Affected Products
- Google Chrome on Windows prior to 152.0.7977.65
- Microsoft Windows hosts running vulnerable Chrome builds
- Enterprise-managed Chrome deployments handling the affected network path
Discovery Timeline
- 2026-08-25 - CVE-2026-78915 published to NVD
- 2026-08-27 - Last updated in NVD database
Technical Details for CVE-2026-78915
Vulnerability Analysis
The vulnerability is a race condition in the Enterprise component of Google Chrome on Windows. Two or more threads access shared state without proper synchronization when handling specific network traffic patterns. An attacker who wins the race can influence memory or object state in a way that breaks the assumptions of the Chrome sandbox boundary.
Successful exploitation results in code execution outside the sandbox. This bypasses the primary containment control that isolates untrusted web content from the underlying Windows operating system. The attack requires adjacent-network positioning, meaning the attacker must reach the target from the same broadcast domain, VLAN, or Wi-Fi segment.
Exploitation complexity is high because race conditions depend on precise thread timing, memory layout, and network delivery windows. No public proof-of-concept exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Root Cause
The root cause is missing or insufficient locking around shared data structures in the Enterprise networking code path. Concurrent operations reach a Time-of-Check Time-of-Use (TOCTOU) style state where validated data is modified before it is used, corrupting sandbox-relevant state.
Attack Vector
An adjacent attacker sends crafted network traffic to a Windows host running a vulnerable Chrome build. The traffic pattern triggers the concurrent code path in the Enterprise component. When the race resolves in the attacker's favor, sandbox-enforced boundaries no longer hold and attacker-controlled logic executes with elevated context.
No verified public exploit code is available. Refer to the Chromium Issue Tracker #533418127 and the Google Chrome Stable Channel Update for vendor technical details.
Detection Methods for CVE-2026-78915
Indicators of Compromise
- Chrome browser processes on Windows spawning unexpected child processes outside the standard renderer or utility sandbox hierarchy
- Anomalous outbound connections from chrome.exe immediately after receiving unusual inbound traffic on adjacent network segments
- Crash dumps or Windows Error Reporting events referencing Chrome Enterprise networking modules with race-related access violations
- Presence of Chrome versions below 152.0.7977.65 on managed Windows endpoints
Detection Strategies
- Inventory installed Chrome versions across the fleet and flag any host running a version prior to 152.0.7977.65.
- Monitor for parent-child process relationships where chrome.exe launches non-standard binaries or shells.
- Correlate broadcast-domain network anomalies with Chrome crash telemetry to surface possible exploitation attempts.
Monitoring Recommendations
- Ingest Chrome update and version telemetry into a central data lake for continuous version-drift monitoring.
- Alert on Chrome sandbox integrity events, unexpected token elevation, or module load anomalies within chrome.exe.
- Track adjacent-network traffic to endpoints, including Wi-Fi and VLAN peers, for crafted or malformed packets targeting browsers.
How to Mitigate CVE-2026-78915
Immediate Actions Required
- Update Google Chrome on all Windows endpoints to version 152.0.7977.65 or later.
- Force enterprise-managed Chrome installations to pull the latest stable channel via Group Policy or the admin console.
- Verify successful update deployment through endpoint inventory and remove or isolate hosts that cannot be patched.
Patch Information
Google released the fix in Chrome Stable channel version 152.0.7977.65 for Windows. Details are published in the Chrome Stable Channel Update for Desktop. Enterprises using managed Chrome should confirm the update rollout ring covers all Windows tiers.
Workarounds
- Restrict Windows endpoints to trusted network segments and disable connections to untrusted Wi-Fi where adjacent attackers could position themselves.
- Enforce network segmentation and 802.1X so unmanaged devices cannot share broadcast domains with corporate endpoints.
- Consider temporarily restricting Chrome usage on high-value hosts until patch deployment completes.
# Verify installed Chrome version on Windows via PowerShell
(Get-Item "C:\Program Files\Google\Chrome\Application\chrome.exe").VersionInfo.ProductVersion
# Trigger Chrome update check silently on managed endpoints
"C:\Program Files (x86)\Google\Update\GoogleUpdate.exe" /ua /installsource scheduler
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
