CVE-2026-87640 in Chrome
Summary
by MITRE • 09/09/2026
Out of bounds read in WebView in Google Chrome on on Android prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to read memory 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 identified as an out-of-bounds read within Google Chrome's WebView component on Android represents a significant breach of browser isolation principles, specifically affecting versions prior to 153.0.8010.36. This flaw resides in the rendering engine and allows for memory corruption that can be exploited by malicious web content. The core technical issue involves improper bounds checking when accessing arrays or buffers within the WebView implementation. When a crafted HTML page is processed, the renderer process fails to verify that data access requests remain within the allocated memory boundaries. Consequently, this oversight permits the reading of arbitrary memory locations that lie outside the intended scope of the current object or buffer.
From an operational security perspective, the severity of this vulnerability is heavily influenced by the sandboxing architecture inherent in modern web browsers. Google Chrome employs a multi-process architecture where renderer processes are isolated from sensitive system resources and other browser components through strict sandboxing mechanisms. The description notes that exploitation requires the attacker to have already compromised the renderer process. This implies that the initial entry point likely involves a separate vulnerability, such as a cross-site scripting attack or a drive-by download that successfully executes malicious code within the untrusted renderer context. Once inside this restricted environment, the out-of-bounds read serves as an escalation vector, allowing the attacker to leak sensitive information from memory regions that should remain inaccessible due to sandbox restrictions.
The impact of exploiting this flaw extends beyond simple data leakage. By reading memory outside the sandbox boundaries, an attacker can potentially extract cryptographic keys, session tokens, or other confidential data stored in adjacent memory spaces. Furthermore, out-of-bounds reads are frequently precursors to more severe exploits, such as arbitrary code execution. While the immediate effect is information disclosure, the ability to inspect arbitrary memory addresses provides attackers with valuable intelligence about the application's layout and state, which can be leveraged to bypass additional security mitigations like Address Space Layout Randomization or Data Execution Prevention in subsequent attack stages.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-125, which describes Out-of-bounds Read. It also maps to MITRE ATT&CK techniques related to Credential Access and Discovery within the browser environment. Specifically, it falls under tactics that involve stealing user credentials or sensitive information from local systems through memory scraping. The exploitation chain typically begins with a remote attack vector via a crafted web page, leveraging the trust users place in legitimate websites or compromised ad networks to deliver the malicious payload.
Mitigation for this vulnerability primarily relies on timely software updates. Users and administrators of Android devices running Google Chrome must upgrade to version 153.0.8010.36 or later, where the bounds checking logic has been corrected to prevent access to memory regions outside allocated limits. In environments where immediate patching is not feasible, defense-in-depth strategies should be employed. These include enforcing strict Content Security Policies to minimize the impact of potential script injections that could trigger such vulnerabilities, utilizing browser extensions that block known malicious domains, and ensuring that operating system-level sandboxing features are fully enabled and configured correctly. Regular security audits and penetration testing focused on web application input validation can also help identify similar implementation flaws before they are exploited in the wild.