CVE-2026-91719 in Chrome
Summary
by MITRE • 09/15/2026
Code injection in XML in Google Chrome prior to 153.0.8010.47 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified as code injection within the Extensible Markup Language processing engine of Google Chrome prior to version 153.0.8010.47 represents a significant deviation from expected browser isolation boundaries. This flaw specifically impacts the XML parser component, which is responsible for interpreting and rendering structured data formats commonly used in web applications for configuration, data exchange, and dynamic content delivery. When an attacker crafts a malicious HTML page that triggers specific parsing behaviors within this engine, they can exploit inconsistencies in how the browser handles mixed content types or improperly sanitized inputs during the XML transformation process. The core technical flaw lies in the failure to adequately enforce separation between script execution contexts and static data structures, allowing injected code to escape its intended scope and execute with higher privileges than a standard web page would normally possess.
From an operational perspective, this vulnerability enables a remote attacker to bypass the Web Origin Policy, a fundamental security mechanism designed to restrict how documents or scripts loaded from one origin interact with resources from another origin. By successfully injecting executable code into the context of a victim's browsing session through a crafted HTML payload, the attacker gains the ability to read sensitive data stored in cookies, local storage, or IndexedDB belonging to other domains that are accessible via the same browser instance. This effectively neutralizes the Same-Origin Policy protections that prevent cross-site scripting attacks and unauthorized data access across different websites. The severity is classified as low by Chromium security standards because successful exploitation typically requires user interaction, such as clicking a link or visiting a specifically designed webpage, rather than being fully automatic through drive-by downloads alone. However, the impact remains critical for any application relying on strict isolation between third-party scripts and first-party data contexts.
This vulnerability aligns with Common Weakness Enumeration category CWE-94, which describes Improper Control of Generation of Code or Script, often referred to as code injection. It also maps closely to MITRE ATT&CK technique T1059, specifically sub-techniques related to command and script interpretation within the browser environment. The attack vector leverages the trust relationship between the user agent and the content it renders, exploiting a logic error in how XML namespaces or entity expansions are processed relative to JavaScript execution contexts. In many cases, such vulnerabilities arise from complex interactions between different rendering engines or when legacy parsing modes are inadvertently activated for modern web standards.
Mitigation strategies primarily involve upgrading Google Chrome to version 153.0.8010.47 or later, where the underlying XML parser logic has been hardened to strictly isolate script execution from data interpretation. For organizations unable to immediately patch all endpoints, implementing strict Content Security Policy headers can help mitigate some downstream effects by restricting the sources from which scripts are allowed to load and execute. Additionally, developers should ensure that any server-side processing of user-supplied XML input performs rigorous validation against expected schemas and disables external entity resolution if not explicitly required for business logic. Users should remain cautious when interacting with untrusted HTML content or files downloaded from unknown sources, as these serve as the primary delivery mechanism for this type of origin bypass exploit. Regular security updates and maintaining up-to-date browser versions are the most effective defenses against such memory corruption and logical flaws in web rendering engines.