CVE-2026-110143 in Chrome
Summary
by MITRE • 10/13/2026
Use of uninitialized variable in ThirdParty lmza_sdk in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to potentially read memory inside the sandbox via a crafted file. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified as an uninitialized variable usage within the ThirdParty lmza_sdk component of Google Chrome represents a significant risk to application integrity and user privacy. This flaw exists in versions prior to 155.0.8059.79 and stems from improper initialization of memory variables during the processing of compressed data streams handled by the Lempel-Ziv-Markov chain algorithm implementation. When an attacker crafts a specific file designed to trigger this code path, the application fails to properly initialize certain internal state variables before they are read or used in subsequent operations. This oversight creates a scenario where sensitive information residing in previously allocated memory blocks can be exposed rather than being zeroed out or set to safe default values.
From a technical perspective, this issue falls under CWE-457, which describes the use of an uninitialized variable. In the context of Chrome's architecture, the browser operates with multiple sandboxing layers designed to restrict the privileges of renderer processes and third-party plugins. The lmza_sdk is often invoked when handling archive files or compressed content within these restricted environments. By exploiting the uninitialized memory read, a remote attacker can bypass expected security boundaries. Although the vulnerability occurs inside the sandbox, the ability to leak arbitrary memory contents from that context allows for information disclosure that can be leveraged for further attacks. The severity is classified as High because it enables an attacker to potentially exfiltrate sensitive data such as cookies, session tokens, or other confidential user information stored in browser memory without requiring direct access to the host operating system's kernel space.
The operational impact of this vulnerability centers on confidentiality and potential downstream exploitation. An attacker hosting a malicious webpage could lure a victim into opening a crafted file that triggers the bug during decompression. Once triggered, the uninitialized variable allows the reading of adjacent memory regions, effectively creating an information leak channel within the sandboxed environment. This capability undermines the isolation guarantees provided by Chrome's security model. While the immediate effect is data leakage, such vulnerabilities are frequently used as stepping stones for more complex attacks, including cross-site scripting or remote code execution if combined with other flaws in the rendering engine or JavaScript interpreter. The lack of proper initialization means that whatever garbage value happens to reside at that memory address is returned, which could include pointers, cryptographic keys, or user credentials depending on what was previously stored there.
Mitigation strategies primarily involve updating the browser software to version 155.0.8059.79 or later, where this specific initialization logic has been corrected by Google's engineering team. For organizations managing large fleets of Chrome browsers, enforcing automatic updates through group policy settings is recommended to ensure all endpoints are protected against known vulnerabilities in third-party libraries like lmza_sdk. Additionally, security teams should monitor for indicators of compromise related to unusual memory access patterns or unexpected network traffic originating from browser processes, which might signal active exploitation attempts. Implementing strict content security policies and restricting the types of files users can open directly within the browser also reduces the attack surface associated with processing untrusted compressed archives. Regular patch management remains the most effective defense against such logic errors in widely used third-party components.