CVE-2026-87494 in Chrome
Summary
by MITRE • 09/09/2026
Use after free in Browser in Google Chrome on on Windows prior to 153.0.8010.36 allowed a remote attacker leveraging social engineering to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability described constitutes a critical memory safety flaw within the Google Chrome browser engine, specifically identified as an use-after-free condition in the rendering and execution context of web content on Windows systems prior to version 153.0.8010.36. This type of error arises when the application continues to reference a memory block after it has been freed or deallocated by the system. In the complex architecture of modern browsers, which rely heavily on dynamic memory management for rendering HTML and executing JavaScript, such errors can lead to unpredictable behavior, including crashes, data corruption, or more severely, arbitrary code execution. The severity is classified as medium within the Chromium security framework, reflecting its potential impact while acknowledging that exploitation typically requires specific conditions beyond mere presence of the flaw.
From a technical perspective, this vulnerability allows for remote code execution outside the browser's sandbox environment when an attacker leverages social engineering techniques to persuade a user to visit a maliciously crafted HTML page. The attack vector relies on the victim interacting with content designed to trigger the use-after-free condition during memory allocation or deallocation cycles within the browser core. Once triggered, the malformed state of memory allows the attacker to control pointers that reference freed memory regions. By carefully crafting heap structures and exploiting timing windows between free operations and subsequent accesses, an adversary can achieve arbitrary read-write primitives. These primitives are essential for bypassing modern operating system protections such as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR), ultimately leading to the execution of shellcode with the privileges of the current user process.
The operational impact of this vulnerability is significant because it enables an attacker to compromise the integrity and confidentiality of a user's session without requiring local access or administrative rights on the target machine. Since the exploitation involves social engineering, the defense relies heavily on user awareness alongside technical controls. A successful exploit grants the adversary full control over the browser process, which can be used to steal sensitive cookies, credentials stored in autofill fields, and other personal data residing within the browsing context. Furthermore, because the code executes outside the sandbox, it may interact with local system resources depending on how the attacker chains this vulnerability with subsequent exploits or leverages existing weaknesses in associated plugins or extensions that have elevated privileges.
This incident aligns closely with Common Weakness Enumeration (CWE) identifier CWE-416, which defines use-after-free errors as a category of memory corruption vulnerabilities where pointers are used after they point to freed memory. In the context of attack classification under MITRE ATT&CK, this vulnerability facilitates initial access and privilege escalation techniques often associated with T1203 Exploitation for Client Execution. The reliance on social engineering places it within the broader scope of phishing campaigns (T1566) where malicious links or embedded content serve as the delivery mechanism. Defenders must recognize that while the browser sandbox provides a robust layer of defense, sophisticated attackers can still breach these boundaries through memory corruption bugs like this one if they are not promptly patched.
Mitigation strategies primarily involve immediate patching to version 153.0.8010.36 or later, which addresses the underlying memory management logic responsible for the flaw. Organizations should ensure that automatic update mechanisms are enabled and functioning correctly across all endpoints running Google Chrome on Windows. Additionally, security teams should enforce strict content security policies (CSP) to restrict inline scripts and untrusted sources where possible, reducing the attack surface available to attackers attempting to deliver malicious HTML payloads. User education remains critical; employees must be trained to recognize suspicious links and avoid visiting unverified websites that may host such crafted pages. Monitoring for anomalous browser behavior or unexpected network connections from chrome.exe processes can also aid in detecting potential exploitation attempts in real-time before full compromise occurs.