CVE-2026-79123 in Chrome
Summary
by MITRE • 08/26/2026
Improper input validation in NTP Footer in Google Chrome on on Windows prior to 152.0.7977.65 allowed a remote attacker who had compromised the renderer process to bypass web origin policy via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an improper input validation flaw within the Network Time Protocol footer handling in Google Chrome for Windows prior to version 152.0.7977.65 represents a significant breach of browser isolation principles. Although NTP is primarily associated with time synchronization, its integration into the rendering engine's internal data structures or logging mechanisms can create unexpected attack surfaces if input sanitization is insufficient. In this specific instance, the flaw allows for an escape from the renderer process sandbox, which is designed to restrict untrusted web content from accessing sensitive system resources or other browser processes. The severity of this issue is classified as low by Chromium security standards because it requires a pre-existing compromise of the renderer process, indicating that the attacker must already have achieved code execution within the isolated environment before exploiting this specific validation error to escalate privileges or break out into higher-privilege contexts such as the browser main process or host system.
From a technical perspective, improper input validation occurs when software fails to correctly verify, filter, or sanitize data received from external sources before processing it. In the context of Chrome's architecture, the renderer process handles web content and is heavily sandboxed to prevent malicious scripts from affecting the rest of the system. The vulnerability likely stems from a failure to properly validate parameters associated with NTP-related structures or headers passed between components within the browser engine. When an attacker crafts a specific HTML page containing malicious code designed to trigger this validation bypass, they can manipulate internal state variables or memory buffers in a way that circumvents security checks. This manipulation enables the execution of arbitrary commands outside the sandboxed environment, effectively allowing the remote attacker to access resources that should remain protected by web origin policies and process isolation boundaries.
The operational impact of this vulnerability is tied directly to the concept of defense-in-depth within modern browsers. While a low-severity rating suggests limited direct exploitability without prior compromise, the ability to bypass web origin policy poses serious risks if combined with other vulnerabilities or social engineering tactics that lead to renderer compromise. Once an attacker escapes the sandbox, they may gain access to cookies, local storage, clipboard data, or even execute files on the host machine depending on the specific privileges of the browser process and user context. This undermines the fundamental trust model of web browsing, where users expect their private data and system integrity to remain secure despite visiting potentially malicious websites. The existence of such a flaw highlights the complexity of maintaining strict boundaries in large codebases like Chromium, where interactions between different subsystems can introduce subtle logic errors that security researchers may exploit for privilege escalation or information disclosure.
Mitigation strategies primarily involve applying the official patch provided by Google to update Chrome to version 152.0.7977.65 or later on Windows systems. Organizations should ensure automated update mechanisms are enabled to minimize the window of exposure. Additionally, users can employ browser hardening techniques such as disabling JavaScript for untrusted sites using extensions like NoScript, although this may impact usability. From a defensive engineering standpoint, developers must enforce strict input validation and type checking at all boundaries between trusted and untrusted code segments. Implementing robust fuzzing campaigns targeting NTP-related structures and other less commonly tested components can help identify similar flaws before they are exploited in the wild. Security teams should also monitor for indicators of compromise related to renderer process escapes, such as unusual memory allocations or unexpected network connections originating from browser processes, which may signal active exploitation attempts against this vulnerability class.
This incident aligns with common weakness enumerations regarding input validation failures and sandbox escape techniques often documented under CWE-20 Improper Input Validation and CWE-787 Out-of-bounds Write if memory corruption is involved in the bypass mechanism. In terms of adversary tactics, it relates to ATT&CK technique T1059 Command and Scripting Interpreter for initial execution within the renderer and potentially T1068 Exploitation for Privilege Escalation if the escape leads to higher-level access. Understanding these mappings helps security professionals contextualize the threat landscape and prioritize remediation efforts based on both technical severity and potential business impact. Continuous monitoring of browser update notifications and adherence to vendor-recommended configuration baselines remain critical defenses against such vulnerabilities that exploit architectural complexities in widely used software applications.