CVE-2025-6555: Google Chrome Use After Free Vulnerability

CVE-2025-6555 Overview

CVE-2025-6555 is a use-after-free vulnerability in the Animation component of Google Chrome prior to version 138.0.7204.49. A remote attacker can trigger heap corruption by serving a crafted HTML page to a target user. Google classifies the Chromium security severity as Medium, and the CVE is tracked under [CWE-416: Use After Free]. Exploitation requires user interaction, specifically navigating to or rendering attacker-controlled content. Successful exploitation can lead to memory corruption that affects the confidentiality and integrity of data within the renderer process.

Critical Impact
Remote attackers can trigger heap corruption in Chrome's Animation component through a crafted HTML page, potentially leading to memory disclosure or code execution within the renderer sandbox.

Affected Products

Google Chrome desktop versions prior to 138.0.7204.49
Chromium-based browsers that incorporate the vulnerable Animation component
All supported desktop platforms (Windows, macOS, Linux) running affected Chrome builds

Discovery Timeline

2025-06-24 - CVE-2025-6555 published to the National Vulnerability Database
2025-06-24 - Google released the Stable Channel update for desktop addressing this issue
2025-07-02 - Last updated in NVD database

Technical Details for CVE-2025-6555

Vulnerability Analysis

The flaw resides in Chrome's Animation subsystem, which manages CSS and Web Animations API timing, keyframes, and effect targets. A use-after-free condition occurs when a heap-allocated object associated with an animation is freed while another code path still holds a dangling reference. Subsequent access to that freed memory results in undefined behavior and heap corruption.

An attacker controls the lifecycle of animation objects through scripted DOM manipulation. By creating, mutating, and destroying animations in a specific sequence, the attacker forces the renderer to dereference memory after deallocation. This typically allows reading or overwriting adjacent heap chunks within the renderer process.

Root Cause

The root cause is improper object lifetime management within the Animation component, tracked in Chromium Issue Tracker #407328533. The vulnerable code releases an object while leaving references reachable from JavaScript-driven event paths or animation timing callbacks. The patch enforces stronger reference handling so the object remains valid for the duration of all dependent operations.

Attack Vector

Exploitation is network-based and requires user interaction. A victim must load attacker-controlled HTML, typically by visiting a malicious website or rendering a compromised advertisement or iframe. The crafted page issues a sequence of DOM, CSS animation, and Web Animations API calls that triggers the dangling pointer. Heap corruption inside the renderer is generally constrained by Chrome's sandbox but can be chained with sandbox escapes for higher impact.

No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2025-6555

Indicators of Compromise

Chrome renderer process crashes (chrome.exe or chrome child processes) with heap corruption signatures shortly after visiting an untrusted URL.
Browser telemetry showing repeated visits to pages that aggressively manipulate animations or trigger renderer restarts.
Unexpected child processes spawned from Chrome following a navigation event, which may indicate a chained sandbox escape.

Detection Strategies

Inventory installed Chrome versions across managed endpoints and flag any build below 138.0.7204.49.
Monitor endpoint logs for renderer crash dumps and correlate them with browsing activity to identify exploitation attempts.
Inspect web proxy and DNS logs for connections to newly registered or low-reputation domains hosting HTML that references Web Animations API objects in suspicious patterns.

Monitoring Recommendations

Enable browser version reporting through enterprise management policies and forward events to a centralized log platform.
Alert on Chrome process crashes that include heap-related exception codes such as STATUS_HEAP_CORRUPTION on Windows.
Track outbound network activity from Chrome child processes for anomalous post-exploitation behavior, including unexpected file writes or process creations.

How to Mitigate CVE-2025-6555

Immediate Actions Required

Update Google Chrome to version 138.0.7204.49 or later on all Windows, macOS, and Linux endpoints.
Force a browser restart after deploying the update, since Chrome only applies patches once the process is relaunched.
Audit Chromium-based browsers and Electron applications for inclusion of the patched Chromium baseline.

Patch Information

Google addressed the vulnerability in the Stable Channel update published on June 24, 2025. Refer to the Google Chrome Desktop Update advisory for release details. Technical context is tracked in Chromium Issue Tracker #407328533.

Workarounds

Restrict browsing to trusted sites through enterprise web filtering until the patch is deployed.
Disable JavaScript on untrusted origins via Chrome enterprise policy to block the script-driven trigger.
Apply site isolation and ensure the renderer sandbox is enabled to limit the impact of heap corruption.

bash

# Verify Chrome version on Linux endpoints
google-chrome --version

# Windows: query installed Chrome version via registry
reg query "HKLM\Software\Google\Update\Clients\{8A69D345-D564-463C-AFF1-A69D9E530F96}" /v pv