CVE-2026-87634 in Chrome
Summary
by MITRE • 09/09/2026
Use after free in WebPackaging in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as a use-after-free flaw within WebPackaging in Google Chrome prior to version 153.0.8010.36 represents a critical memory management error that undermines the browser's sandboxing mechanisms. This specific class of vulnerabilities is formally categorized under CWE-416, which describes situations where a program continues to use a pointer after it has been freed or deallocated from memory. In the context of modern web browsers like Chrome, such errors are particularly dangerous because they can allow an attacker to manipulate internal data structures in ways that bypass security boundaries designed to isolate untrusted content from system resources.
WebPackaging is a feature intended to facilitate the distribution and installation of Progressive Web Apps by allowing developers to package their applications into installable formats. The flaw arises when Chrome fails to properly manage the lifecycle of memory objects associated with this packaging process. Specifically, an object is freed while there are still active references or pointers to it within the browser's internal state. When a remote attacker crafts a malicious HTML page that triggers specific interactions with WebPackaging APIs, they can cause the application to access and potentially overwrite data at the memory location previously occupied by the freed object. This scenario creates an opportunity for arbitrary code execution because the attacker can control the content written into this reused memory space through carefully crafted input vectors embedded in the malicious webpage.
The operational impact of this vulnerability is severe due to its potential to escape the browser's sandbox environment. Chrome relies heavily on process isolation and sandboxing to limit the damage caused by compromised web pages. By exploiting a use-after-free condition, an attacker can achieve arbitrary code execution with the privileges of the current user but outside these protective boundaries. This means that instead of being confined to a restricted context where actions are limited, the malicious payload gains broader access to system resources, potentially leading to full device compromise, data exfiltration, or further lateral movement within a network if the browser is used in an enterprise environment. The Chromium project has classified this security issue with a severity rating of Low, likely reflecting its complexity or the specific conditions required for successful exploitation, but the underlying risk remains significant given the potential for sandbox escape.
From a threat intelligence perspective, this vulnerability aligns with ATT&CK techniques related to initial access and execution via web-based attacks. Attackers typically leverage social engineering tactics combined with malicious HTML pages hosted on compromised websites or phishing campaigns to deliver the exploit code. The use of crafted HTML serves as the delivery mechanism for triggering the memory corruption flaw within the WebPackaging component. Defenders should be aware that such vulnerabilities are often targeted in zero-day exploits where the specific trigger conditions might not yet be widely known, making proactive mitigation essential even before widespread patching occurs across all user bases.
To mitigate this risk, organizations and individual users must ensure that Google Chrome is updated to version 153.0.8010.36 or later immediately upon availability. This update contains the necessary code changes to properly manage memory allocation and deallocation within the WebPackaging module, thereby eliminating the window of opportunity for use-after-free exploitation. Additionally, security teams should enforce strict content security policies and consider deploying browser isolation solutions that further restrict what web pages can interact with native system components. Regular vulnerability scanning and patch management cycles are critical to closing these gaps before they can be leveraged in targeted attacks. Monitoring network traffic for unusual outbound connections following visits to untrusted sites may also provide early indicators of compromise resulting from such exploits.