CVE-2026-87440 in Chrome
Summary
by MITRE • 09/09/2026
Out of bounds read in Media in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an out-of-bounds read within the Media component of Google Chrome prior to version 153.0.8010.36 represents a critical memory safety flaw that undermines the browser's sandboxing mechanisms. This type of error occurs when software reads data from a memory location beyond the intended boundaries of a buffer or array, often due to improper index validation or incorrect calculation of memory offsets during media processing operations. In the context of web browsers, such flaws are particularly dangerous because they can be triggered by maliciously crafted content embedded in standard HTML pages. When an attacker constructs a webpage containing specially designed media elements or scripts that manipulate how Chrome processes audio and video data, it can cause the browser to access memory regions it should not touch, leading to unauthorized information disclosure or more severe consequences depending on the specific state of the heap at the time of exploitation.
From a technical perspective, this vulnerability is classified under CWE-125, which denotes Out-of-bounds Read. This category encompasses situations where an application reads data past the end of a buffer, potentially leaking sensitive information from adjacent memory structures or causing undefined behavior that can be leveraged for further attacks. The severity rating of High by Chromium security reflects the potential impact on system integrity and confidentiality. While out-of-bounds reads are often associated with information leaks, in modern browser environments involving complex rendering engines like Blink and V8 JavaScript engine, they frequently serve as a precursor to arbitrary code execution if combined with other techniques such as heap spraying or type confusion attacks. The attacker's ability to control the content of an HTML page allows them to precisely craft inputs that trigger this memory violation at critical moments during media decoding or playback routines.
The operational impact of this vulnerability is significant because it bypasses one of the primary defenses against web-based attacks: sandboxing. Google Chrome employs a multi-process architecture where renderer processes are isolated from the operating system and other browser components to limit the damage caused by successful exploits. However, if an out-of-bounds read allows an attacker to leak pointers or sensitive data structures from higher-privilege contexts or within the same process space in a way that facilitates memory corruption, it can lead to arbitrary code execution inside the sandbox. This means that even though the malicious script runs in a restricted environment, the exploitation of this flaw could allow the attacker to escape these restrictions and execute commands with the privileges of the user running the browser. Such an outcome compromises not only the confidentiality of browsing data but also the integrity of the entire system by allowing malware installation or remote access capabilities.
This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly those related to initial access and privilege escalation via web-based attacks. Attackers often distribute malicious HTML pages through phishing campaigns, compromised websites, or drive-by downloads to exploit such browser vulnerabilities without requiring user interaction beyond visiting a page. The use of crafted media elements suggests an attempt to abuse the complexity of multimedia processing libraries within Chrome, which are frequent targets for exploitation due to their intricate handling of binary data formats. Understanding this vector is crucial for defenders who monitor network traffic and endpoint behavior for signs of exploit attempts targeting browser components.
Mitigation strategies primarily involve ensuring that all instances of Google Chrome are updated to version 153.0.8010.36 or later, where the underlying memory management issues in the Media component have been patched by developers. Organizations should enforce automatic update policies for browsers across their endpoints to minimize exposure windows. Additionally, users can reduce risk by disabling unnecessary plugins and media features if they are not required for daily tasks, although this is often impractical given modern web dependencies. Security teams should also monitor for indicators of compromise associated with known exploit kits that target Chrome vulnerabilities, including unusual network connections from browser processes or unexpected child process spawns following visits to untrusted sites. Regular security awareness training regarding suspicious links and attachments remains a vital complementary control against social engineering tactics used to deliver such malicious HTML pages.