CVE-2026-113054 in Chrome
Summary
by MITRE • 10/21/2026
Out of bounds read in SiteIsolation in Google Chrome prior to 156.0.8078.47 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 • 10/21/2026
The vulnerability identified as an out-of-bounds read within the Site Isolation component of Google Chrome prior to version 156.0.8078.47 represents a significant breach in browser memory safety protocols. This flaw occurs when the browser engine processes specific HTML content that triggers incorrect boundary checks during the isolation process, which is designed to separate browsing contexts from different origins into distinct renderer processes. By crafting an HTML page with carefully constructed inputs, a remote attacker can exploit this logic error to cause the application to read beyond the allocated memory buffer boundaries. This type of vulnerability falls under the Common Weakness Enumeration category CWE-125, which describes out-of-bounds read operations that allow access to sensitive data outside the intended scope.
The operational impact of this flaw is particularly severe due to its interaction with Chrome's sandboxing architecture. Site Isolation is a critical security feature that prevents cross-site scripting and other attacks by ensuring that pages from different sites are rendered in separate processes, thereby limiting the damage an attacker can cause if they successfully exploit a vulnerability on one site. However, when an out-of-bounds read occurs within this isolation mechanism, it allows a remote attacker to bypass these sandbox boundaries. The attacker gains the ability to leak memory contents from inside the sandboxed renderer process, potentially exposing sensitive information such as cookies, session tokens, or other private data associated with the user's browsing activity. This capability effectively neutralizes one of the primary defenses against cross-origin attacks, elevating a medium severity issue into a potential high-impact security breach depending on the specific memory contents accessed.
From an offensive security perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework, specifically those related to unauthorized access and data exfiltration from protected processes. The exploitation path typically involves delivering malicious HTML content through phishing campaigns or compromised websites, where the victim's browser automatically parses the crafted page upon navigation. Once executed, the out-of-bounds read does not necessarily lead to arbitrary code execution but provides a reliable method for information disclosure. This can facilitate further attacks such as session hijacking or credential theft if sensitive data is successfully extracted from memory. The medium severity rating assigned by Chromium reflects that while exploitation requires specific conditions and crafted input, the potential for privacy violation and sandbox escape makes it a priority fix.
Mitigation strategies primarily involve updating to Google Chrome version 156.0.8078.47 or later, where the boundary checks within Site Isolation have been corrected to prevent reading beyond allocated memory regions. Organizations should enforce automatic update policies for all endpoints running this browser to ensure rapid patch deployment. Additionally, security teams can monitor network traffic and endpoint behavior for unusual patterns indicative of exploitation attempts, such as high-frequency requests from specific domains or unexpected memory access anomalies in renderer processes. Implementing strict content security policies and disabling unnecessary JavaScript features on untrusted sites can also reduce the attack surface by limiting the types of scripts that can be executed within isolated contexts. Regular vulnerability assessments and penetration testing focused on browser-based attacks are recommended to identify similar weaknesses before they can be exploited in production environments.