CVE-2026-102318 in Chrome
Summary
by MITRE • 09/29/2026
Out of bounds read in WebGL in Google Chrome prior to 154.0.8037.92 allowed a remote attacker to read memory outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified as an out-of-bounds read within the WebGL subsystem of Google Chrome prior to version 154.0.8037.92 represents a critical breach in memory safety protocols that governs how web content interacts with hardware-accelerated graphics processing units. This specific flaw arises from improper boundary checks during the execution of OpenGL or Vulkan commands translated through the browser's WebGL implementation, allowing an attacker to access memory locations beyond the allocated buffer limits. In modern web browsers, sandboxing is a fundamental security mechanism designed to isolate untrusted content from sensitive system resources and user data. When this isolation fails due to a logic error in how array indices are validated against buffer sizes, it creates a pathway for information disclosure that bypasses standard containment measures.
From a technical perspective, the root cause of this issue lies in the handling of vertex or fragment shader operations where input arrays are not strictly bounded before being processed by the graphics pipeline. An attacker can craft an HTML page containing malicious JavaScript and WebGL code that triggers these unchecked memory accesses. By carefully constructing inputs that exceed the defined array limits but remain within valid address space, the browser's rendering engine may read arbitrary bytes from adjacent memory regions. This behavior aligns with CWE-125, which describes out-of-bounds read vulnerabilities where software reads data past the end or before the beginning of the intended buffer. The severity is classified as high because it directly undermines the integrity and confidentiality guarantees provided by the browser's security model.
The operational impact of this vulnerability extends beyond simple memory corruption to potential remote code execution scenarios, although in this specific instance, the primary risk is information disclosure. An attacker leveraging a crafted webpage could potentially exfiltrate sensitive data such as cookies, session tokens, or other private user information stored in adjacent memory blocks. This capability allows for sophisticated phishing attacks where stolen credentials can be transmitted back to an external server controlled by the adversary. Furthermore, depending on the specific browser version and underlying operating system architecture, out-of-bounds reads can sometimes serve as a precursor to more severe exploits like heap spraying or type confusion attacks, which could lead to arbitrary code execution with the privileges of the current user process.
This vulnerability is closely associated with ATT&CK technique T1059, specifically sub-techniques related to command and script interpreters within browser environments, although it primarily facilitates data exfiltration rather than direct execution at this stage. The exploitation vector requires a remote attacker to trick a victim into visiting a malicious website or clicking on a link that loads the crafted HTML page. This social engineering component is critical because the exploit relies on user interaction to trigger the rendering engine's flawed logic. Once triggered, the browser processes the WebGL commands without adequate validation, leading to the unauthorized memory access. The lack of immediate crash indicates that the read operation was successful but did not cause a segmentation fault, making detection by standard error handlers difficult and increasing the stealthiness of the attack.
Mitigation strategies for this vulnerability primarily involve updating Google Chrome to version 154.0.8037.92 or later, where the boundary checks in the WebGL subsystem have been corrected to ensure that all array accesses are validated against their declared sizes before execution. For organizations unable to update immediately due to compatibility concerns, deploying browser-based security controls such as strict Content Security Policy headers can help mitigate some risks by restricting script execution and resource loading from untrusted sources. Additionally, enabling sandboxing features like Site Isolation ensures that even if a vulnerability is exploited, the impact is contained within a single site's context, preventing access to data belonging to other sites or sensitive system memory. Regular patch management cycles are essential to address such high-severity flaws promptly and maintain robust defense-in-depth posture against web-based attacks.