CVE-2016-5226 in Chrome
Summary
by MITRE
Blink in Google Chrome prior to 55.0.2883.75 for Linux, Windows and Mac executed javascript: URLs entered in the URL bar in the context of the current tab, which allowed a socially engineered user to XSS themselves by dragging and dropping a javascript: URL into the URL bar.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability CVE-2016-5226 represents a critical security flaw in the Blink rendering engine used by Google Chrome across multiple operating systems. This issue specifically affected Chrome versions prior to 55.0.2883.75 and demonstrated how user interface elements could be exploited to bypass traditional security mechanisms. The vulnerability exploited a fundamental design assumption about how users interact with web browsers, particularly in relation to URL handling and execution contexts. The flaw existed in the browser's handling of javascript: URLs entered through the address bar, creating a pathway for malicious or socially engineered attacks that could compromise user sessions.
The technical implementation of this vulnerability involved the Blink engine's processing of javascript: URLs when they were entered directly into the browser's address bar. Under normal circumstances, browsers typically execute javascript: URLs in a context that is separate from the current page's security domain, but in this case, Chrome executed these URLs within the context of the current tab. This behavior created a scenario where users could inadvertently execute malicious code simply by dragging and dropping a javascript: URL into the address bar, a technique that exploited the trust users place in their browser's address bar functionality. The vulnerability specifically targeted the URL bar's handling mechanism and the security boundaries between different execution contexts within the browser's architecture.
The operational impact of this vulnerability was significant as it enabled a form of cross-site scripting attack that required minimal user interaction beyond the simple act of dragging and dropping a malicious URL. Attackers could craft javascript: URLs that would execute code in the context of the user's current browsing session, potentially allowing for session hijacking, credential theft, or arbitrary code execution. The attack vector was particularly insidious because it relied on social engineering rather than complex exploitation techniques, making it accessible to attackers with minimal technical expertise. Users could be tricked into dragging and dropping seemingly benign URLs that contained malicious javascript payloads, leading to immediate compromise of their browser sessions.
This vulnerability aligns with CWE-79 which describes cross-site scripting flaws, specifically addressing the execution of untrusted code in the context of the current user. The attack pattern corresponds to techniques described in the ATT&CK framework under T1059.007 for JavaScript execution and T1566 for social engineering attacks. The security implications extend beyond simple XSS as this vulnerability allowed for privilege escalation within the browser context, potentially enabling attackers to access cookies, local storage, and other session data. The fix implemented by Google involved modifying the URL bar's execution context handling to ensure that javascript: URLs would not execute in the context of the current page, but rather in a more isolated security boundary. Organizations should prioritize updating Chrome installations to version 55.0.2883.75 or later to mitigate this vulnerability, and security teams should consider implementing browser security policies that restrict the execution of javascript: URLs in user-facing interfaces.