CVE-2026-106261 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 to read memory inside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an uninitialized resource issue within the video processing subsystem of Google Chrome prior to version 155.0.8059.39 represents a critical failure in memory management practices during media decoding operations. This flaw stems from improper initialization of internal data structures or buffers used by the browser's multimedia engine when handling specific, crafted HTML content containing maliciously constructed video streams. When an attacker hosts a specially designed web page that triggers this code path, the application fails to properly zero out or initialize certain memory regions before they are accessed for reading operations. This oversight results in the exposure of previously allocated but uninitialized memory contents, which may contain sensitive data from other processes or previous browser sessions residing within the same sandboxed environment.
From a technical perspective, this vulnerability falls under the category of improper initialization leading to information disclosure. It aligns with Common Weakness Enumeration identifier CWE-457, which describes the use of an uninitialized variable that can lead to unpredictable behavior and potential data leakage. The core mechanism involves the video decoder component allocating memory for frame buffers or metadata structures but neglecting to clear them before reuse or initial access. Consequently, when the browser attempts to read from these regions during normal playback processing initiated by the crafted page, it retrieves residual data left over in those memory locations. This behavior effectively bypasses the intended isolation boundaries of the renderer process sandbox because the attacker gains a mechanism to exfiltrate raw memory contents that were not meant for public consumption within the web context.
The operational impact of this vulnerability is significant due to its potential for remote code execution or sensitive data theft via information leakage. Although classified with a medium severity rating by Chromium security teams, the ability to read arbitrary memory inside the sandbox allows an attacker to potentially gather cryptographic keys, session tokens, passwords, or other confidential user data stored in browser memory. Furthermore, such memory disclosure can serve as a stepping stone for more complex attacks, including heap spraying techniques that facilitate remote code execution exploits against the underlying operating system if combined with additional vulnerabilities. The attack vector is entirely remote and requires no user interaction beyond visiting a maliciously crafted website or being redirected to one through phishing campaigns, making it highly scalable in targeted social engineering scenarios.
Mitigation strategies primarily involve immediate software updates to ensure all instances of Google Chrome are upgraded to version 155.0.8059.39 or later where the initialization logic has been corrected by developers. Security administrators should enforce automatic update policies across organizational endpoints to minimize exposure windows. Additionally, users can employ browser hardening techniques such as disabling JavaScript execution on untrusted sites using extensions like NoScript or leveraging Chrome's built-in site isolation features more aggressively to limit cross-origin data access. Monitoring network traffic for unusual outbound connections following visits to suspicious media-heavy websites may also help detect potential exploitation attempts in real-time.
This incident underscores the importance of rigorous memory safety protocols within complex software systems, particularly those handling untrusted multimedia input. The vulnerability maps to MITRE ATT&CK technique T1005, which covers Data from Local System, specifically indicating how attackers can harvest data directly from local system components through application vulnerabilities rather than direct file access. By addressing the root cause of uninitialized memory usage and ensuring timely patch deployment, organizations can significantly reduce their attack surface against sophisticated web-based exploitation campaigns targeting browser infrastructure.