CVE-2026-11655 Overview
CVE-2026-11655 is an integer overflow vulnerability in the Media component of Google Chrome on macOS prior to version 149.0.7827.103. The flaw allows a remote attacker who has already compromised the renderer process to potentially escape the Chrome sandbox through a crafted HTML page. Google classifies the Chromium security severity as High. The vulnerability is tracked under CWE-472, reflecting external control of assumed-immutable values that lead to arithmetic miscalculation. Successful exploitation breaks the renderer sandbox boundary, granting attackers access to the broader macOS host context.
Critical Impact
A compromised renderer can escape the Chrome sandbox on macOS, exposing the host system to further code execution and data theft.
Affected Products
- Google Chrome for macOS prior to 149.0.7827.103
- Apple macOS (host platform required for exploitation)
- Chromium-based browsers on macOS that inherit the vulnerable Media component
Discovery Timeline
- 2026-06-09 - CVE-2026-11655 published to the National Vulnerability Database (NVD)
- 2026-06-09 - Last updated in NVD database
Technical Details for CVE-2026-11655
Vulnerability Analysis
The vulnerability resides in Chrome's Media subsystem on macOS. An integer overflow occurs during the processing of media data, where arithmetic on attacker-influenced values exceeds the bounds of its integer type. The resulting miscomputed value is then used in subsequent memory operations or capability checks within trusted code paths. Exploitation requires the attacker to have already compromised the renderer process, typically through a prior vulnerability chain. Once chained, the integer overflow provides the primitive required to cross the renderer-to-browser process boundary. Sandbox escapes of this class enable attackers to interact with operating system resources outside the sandbox policy, including the file system, IPC channels, and privileged Chrome services. The flaw maps to CWE-472: External Control of Assumed-Immutable Web Parameter in Chromium's classification. EPSS currently estimates a low near-term exploitation probability, but sandbox escape primitives historically attract attention from exploit developers building full chains.
Root Cause
The root cause is an integer overflow in arithmetic performed on values controlled or influenced through media content. The overflowed value is trusted by downstream logic, breaking a memory safety or capability invariant required to maintain sandbox isolation.
Attack Vector
Attack delivery occurs over the network through a crafted HTML page that triggers the vulnerable media processing path. The attacker must first compromise the renderer process and then leverage user interaction with malicious content. The scope changes when sandbox boundaries are crossed, expanding the impact to the host macOS context.
No public proof-of-concept code has been released. See the Chromium Issue Tracker entry for vendor technical details.
Detection Methods for CVE-2026-11655
Indicators of Compromise
- Chrome renderer or GPU helper processes on macOS spawning unexpected child processes outside the standard Chrome process tree
- Crashes in Google Chrome Helper (Renderer) referencing media decoding stack frames
- Unusual file system or IPC access originating from Chrome helper processes after media content is rendered
Detection Strategies
- Inventory installed Chrome versions across macOS endpoints and flag any build below 149.0.7827.103
- Monitor for anomalous parent-child process relationships involving Chrome helper binaries
- Inspect crash reports under ~/Library/Application Support/Google/Chrome/Crashpad for repeated media-related faults
Monitoring Recommendations
- Alert on Chrome helper processes performing privileged file system writes outside expected sandbox paths
- Correlate browser crash telemetry with subsequent process creation events on the same host
- Track outbound network connections from non-renderer Chrome processes initiated immediately after navigation events
How to Mitigate CVE-2026-11655
Immediate Actions Required
- Update Google Chrome on all macOS endpoints to version 149.0.7827.103 or later
- Force-restart Chrome after deployment to ensure the patched binary is loaded into memory
- Validate that managed Chrome deployments are not pinned to vulnerable versions through enterprise policy
Patch Information
Google released the fix in the Chrome Stable channel update referenced in the Google Chrome Update Announcement. Apply Chrome 149.0.7827.103 or later on macOS to remediate the integer overflow in the Media component.
Workarounds
- Restrict navigation to untrusted sites using enterprise URL allowlists until patching is complete
- Enable Chrome's Site Isolation and Strict Origin Isolation policies to limit renderer compromise impact
- Deploy host-based controls on macOS to restrict Chrome helper processes from writing to sensitive directories
# Verify the installed Chrome version on macOS
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version
# Enforce minimum version via MDM-managed Chrome policy (example plist key)
defaults write com.google.Chrome BrowserSignin -int 2
defaults write com.google.Chrome RestrictSigninToPattern -string ".*@example\.com"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
