CVE-2026-91724 in Chrome
Summary
by MITRE • 09/15/2026
Use after free in Input in Google Chrome prior to 153.0.8010.47 allowed a remote attacker who had compromised the renderer process to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described constitutes a critical use-after-free flaw within the input handling subsystem of Google Chrome, specifically affecting versions prior to 153.0.8010.47. This memory corruption issue arises when the browser fails to properly manage the lifecycle of objects associated with user interface elements or form inputs after they have been deallocated from memory. In a typical web browsing scenario, an attacker can craft a malicious HTML page that triggers this specific sequence of events by manipulating DOM structures and event handlers in a way that causes the application to reference freed memory addresses. The severity is classified as high within the Chromium security framework due to the potential for arbitrary code execution, which represents one of the most dangerous outcomes in web browser exploitation scenarios.
From a technical perspective, this vulnerability leverages the complex interaction between JavaScript engines and native C++ components that handle input processing. When an attacker crafts a page designed to exploit this race condition or logic error, they can cause the renderer process to access memory that has already been returned to the heap allocator. If the application subsequently writes data to these stale pointers before the operating system reclaims them for other purposes, it creates an opportunity for controlled memory corruption. This control over memory layout allows the attacker to overwrite function pointers or object vtables, thereby redirecting program execution flow to malicious shellcode injected into the page context.
The operational impact of this vulnerability is severe because it facilitates a sandbox escape scenario. Although modern browsers employ robust security sandboxes that isolate renderer processes from the operating system and user data, a successful exploitation of this use-after-free flaw allows an attacker who has already compromised the renderer process to break out of these restrictions. By executing arbitrary code outside the sandbox, the attacker gains elevated privileges equivalent to those of the browser's main process or even the underlying host system. This means that sensitive information such as cookies, saved passwords, and browsing history can be exfiltrated without user interaction beyond visiting a malicious website.
This type of exploitation aligns with known attack patterns documented in industry standards. It corresponds closely to CWE-416, which defines use-after-free errors where references to memory are used after they have been freed. Furthermore, the technique maps directly to MITRE ATT&CK techniques related to process injection and sandbox evasion, specifically those involving dynamic binary modification or exploitation of client applications for initial access and privilege escalation. The ability to execute code outside the renderer sandbox is a critical milestone in browser-based attacks, often serving as the precursor to full system compromise if not mitigated by additional security layers such as Data Execution Prevention or Address Space Layout Randomization.
Mitigation strategies primarily involve applying the vendor-provided patch that addresses this specific memory management flaw within the input handling code path. Users and administrators should ensure that Google Chrome is updated to version 153.0.8010.47 or later immediately upon availability. Additionally, defense-in-depth measures such as enabling site isolation features in Chromium-based browsers can help limit the blast radius of renderer compromises by ensuring that sensitive data is not accessible across different origins even if a sandbox escape occurs. Regular security audits and fuzzing of input processing modules are also recommended to detect similar memory safety issues before they reach production environments, thereby reducing the attack surface for remote code execution vulnerabilities in web browsers.