CVE-2026-106273 in Chrome
Summary
by MITRE • 10/06/2026
Uninitialized resource in Video in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to read memory outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an uninitialized resource issue within Google Chrome's video processing subsystem prior to version 155.0.8059.39 represents a significant breach in browser isolation mechanisms. This flaw specifically affects the handling of multimedia content, where improper initialization of memory structures leads to undefined behavior during playback or rendering operations. The core technical deficiency lies in the failure to properly zero out or initialize specific data structures associated with video decoding and rendering pipelines before they are utilized by subsequent processing stages. When a crafted HTML page triggers this code path, the browser attempts to access memory locations that have not been correctly set up, resulting in an out-of-bounds read operation. This type of error is classified under CWE-457, which denotes the use of an uninitialized variable, and often falls within the broader category of improper input validation or state management errors common in complex media processing libraries.
The operational impact of this vulnerability is severe due to its potential for sandbox escape. Google Chrome employs a multi-process architecture where renderer processes are confined within a strict security sandbox to prevent malicious code from accessing sensitive system resources or user data. However, when an attacker crafts a specific HTML page that exploits the uninitialized resource in the video component, they can leverage the out-of-bounds read to leak memory contents from outside the intended sandbox boundaries. This capability allows a remote attacker who has already compromised the renderer process through initial vectors such as phishing or drive-by downloads to escalate privileges and access arbitrary memory regions. The ability to read memory beyond the sandbox effectively neutralizes one of the primary defense-in-depth layers provided by modern web browsers, potentially leading to full system compromise if combined with other exploitation techniques like heap spraying or information disclosure attacks.
From a threat intelligence perspective, this vulnerability aligns with ATT&CK technique T1057, which covers Process Discovery and more critically T1042, Content Injection, as well as potential data exfiltration methods under T1005 if the leaked memory contains sensitive user credentials or session tokens. The high severity rating assigned by Chromium security reflects the direct path to sandbox escape, a critical milestone in browser exploitation chains. Attackers typically utilize such vulnerabilities in targeted campaigns where initial access is established via social engineering or compromised websites, followed by the execution of malicious scripts that trigger the video processing flaw. The lack of proper initialization suggests a gap in code review processes for media-related components, highlighting the complexity and risk inherent in integrating third-party codecs and rendering engines into browser architectures.
Mitigation strategies primarily involve immediate patching to version 155.0.8059.39 or later, where Google has addressed the uninitialized resource issue by ensuring proper memory initialization before use. Organizations should enforce automated update policies for all endpoints running Chrome to minimize exposure windows. For environments unable to immediately upgrade, network-level controls such as web application firewalls can be configured to block requests containing suspicious HTML patterns known to trigger video processing exploits, although this is less effective against obfuscated or dynamically generated payloads. Additionally, enabling sandbox enforcement features and restricting the use of legacy plugins that may interact with vulnerable media components can reduce the attack surface. Security teams should also monitor for indicators of compromise related to unusual memory access patterns in renderer processes, as these may signal active exploitation attempts targeting this specific flaw. Continuous monitoring and rapid response capabilities are essential given the high severity and direct impact on browser security boundaries.