Chrome <138.0.7204.157: Insufficient validation of untrusted input in ANGLE and GPU leading to sandbox escape (CVE-2025-6558) #shorts

Summary

CVE-2025-6558 is a critical zero-day vulnerability in Google Chrome’s ANGLE and GPU components that allows a remote attacker to escape the browser sandbox via a specially crafted HTML page. This is the fifth Chrome zero-day patched by Google this year, and there is evidence of active exploitation in the wild. Debian has issued a security update for its Chromium package to address this and related RCE and DoS flaws.

Product details

Affected product: Google Chrome versions prior to 138.0.7204.157 (custom version type). Upstream vendor: Google. Debian maintainer: Debian security team, which released an update for the Chromium package to include the Chrome 138.0.7204.157 fix.

Vulnerability type summary

The issue is classified as "Insufficient validation of untrusted input" in the ANGLE and GPU subsystems of Chrome. It has a Chromium security severity rating of High and can lead to a sandbox escape, a critical form of privilege escalation within the browser environment.

Details of the vulnerability

A flaw in the way Chrome’s ANGLE and GPU processes validate external data allows an attacker to craft a malicious HTML page that triggers out-of-bounds or malformed data handling. By exploiting this, an attacker can break out of the renderer sandbox and execute arbitrary code on the host system. Google’s July 15, 2025 patch (138.0.7204.157) corrects the input validation routines. This vulnerability was under active exploitation at the time of disclosure, making it a priority for immediate patching. Debian’s security update also covers this issue alongside other critical RCE and denial-of-service vulnerabilities in upstream Chromium.

Conclusion

Users and administrators should immediately update to Google Chrome 138.0.7204.157 or later. Debian and other Linux distributions should install the latest Chromium security patch. Staying current with browser updates is crucial to mitigate active zero-day threats and maintain a secure browsing environment.

Watch the full video on YouTube: CVE-2025-6558

Remediation and exploitation details

This chain involves the following actors

  • Remote attacker: Launches the crafted HTML payload to exploit the vulnerability
  • End user: Loads the malicious web page in their browser

This following systems are involved

  • ANGLE (Translates web graphics API calls into hardware commands): Processes untrusted WebGL input from web pages
  • GPU process (Executes graphics operations in an isolated process): Parses command buffers and enforces sandbox boundaries
  • Sandbox (Contains processes to limit privilege and access): Restricts GPU process activities after input validation

Attack entry point

  • Crafted HTML page: A web page containing specially constructed WebGL calls and shader code that trigger insufficient validation in ANGLE and the GPU process

Remediation actions

End user
Update Google Chrome to version 138.0.7204.157 or later
Google Chrome
System administrator
Apply the Debian security update for Chromium
Chromium on Debian

Exploitation actions

Drive-by download of malicious WebGL content

Remote attacker
Hosts a malicious web page and entices the victim to visit
Crafted HTML page
Examples:
  • Phishing email with link to compromised site
  • Malicious advertisement on legitimate website

Feed out-of-range or malformed data to the graphics translation layer

Remote attacker
Injects invalid parameters into WebGL calls and shader instructions
ANGLE
Examples:
  • Texture dimensions exceeding allowed limits
  • Shader uniform counts that mismatch buffer size

Cause a buffer overflow or heap corruption during command decoding

Remote attacker
Triggers the GPU process to parse the malicious command buffer
GPU process
Examples:
  • Crafted draw call with excessive vertex count
  • Malformed buffer length field in command stream

Overwrite validation flags or function pointers to disable boundary enforcement

Remote attacker
Corrupts internal GPU process memory structures used for sandbox checks
Sandbox
Examples:
  • Altered permission bits to allow file system access
  • Redirected control flow to unrestricted code paths

Leverage corrupted pointers or use-after-free to gain code execution

Remote attacker
Escapes the GPU sandbox and executes arbitrary code on the host system
Browser or operating system
Examples:
  • Spawn a new process with elevated privileges
  • Inject malicious payload into system memory

Related Content

NOTE: The following related content has not been vetted and may be unsafe.

CVE database technical details

CVE ID
CVE-2025-6558
Description
Insufficient validation of untrusted input in ANGLE and GPU in Google Chrome prior to 138.0.7204.157 allowed a remote attacker to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)
Provider
Chrome
CWE / problem types
Insufficient validation of untrusted input
Affected Software Versions
Google:Chrome:[{'version': '138.0.7204.157', 'status': 'affected', 'lessThan': '138.0.7204.157', 'versionType': 'custom'}]
Date Published
2025-07-15T18:12:36.848Z
Last Updated
2025-07-16T03:56:06.674Z