CVE-2026-117980 in Firefox
Summary
by MITRE • 10/27/2026
Use-after-free in the Graphics component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/27/2026
The identified vulnerability represents a critical memory management error classified as an out-of-bounds write, specifically manifesting through a use-after-free condition within the browser's graphics subsystem. In software engineering, particularly in systems written in languages like C and C++ which are common for high-performance rendering engines such as Mozilla’s Gecko or WebRender, proper lifecycle management of allocated memory is paramount. A use-after-free vulnerability occurs when an application continues to use a pointer after the memory it points to has been freed. In this specific context, the graphics component likely retained a reference to a buffer or object that had already been deallocated by another part of the system due to race conditions or incorrect state transitions during rendering operations. When the program subsequently attempts to write data to this stale memory address, it results in an out-of-bounds write because the freed memory may have been reallocated for different purposes or simply marked as available without being zeroed out, leading to unpredictable behavior and potential corruption of adjacent memory structures.
From a security architecture perspective, this flaw aligns with Common Weakness Enumeration (CWE) identifier CWE-416, which denotes use after free issues that can lead to arbitrary code execution if exploited effectively. The operational impact of such a vulnerability is severe because the graphics stack processes complex data streams from web content, including images, videos, and canvas elements. An attacker who could craft malicious web content designed to trigger this specific race condition or state error might achieve remote code execution on the victim's machine with the privileges of the browser process. This bypasses many traditional sandboxing mechanisms if the graphics component operates with elevated permissions necessary for hardware acceleration. The vulnerability essentially allows an adversary to manipulate memory layout, potentially overwriting function pointers or object vtables, which are common techniques in exploitation chains leading to full system compromise.
This type of defect is frequently associated with advanced persistent threats and sophisticated phishing campaigns that utilize zero-day exploits before patches are available. In the context of the MITRE ATT&CK framework, this vulnerability facilitates initial access and execution tactics by allowing attackers to execute arbitrary code within a trusted application environment. The browser acts as an attack surface where untrusted web content is rendered; therefore, any flaw in how that rendering engine handles memory directly impacts the trust boundary between the user's local system and the internet. Exploitation typically requires social engineering elements such as convincing a user to visit a specially crafted website or open a malicious document that triggers the graphics processing pipeline under specific conditions that expose the timing window for the use-after-free condition.
Mitigation strategies primarily involve applying the vendor-provided updates, which in this case are Firefox version 159 and Firefox Extended Support Release (ESR) version 153.6. These patches likely include rigorous memory safety checks, such as adding null pointer validations after deallocation or implementing smart pointers that automatically manage object lifecycles to prevent dangling references. For organizations relying on the ESR branch, immediate deployment of this update is critical to close the security gap in enterprise environments where browsers are used for daily operations. Additionally, users should ensure their operating systems and graphics drivers are up to date, as modern OS-level mitigations like Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) can raise the bar for successful exploitation by making memory layout unpredictable and preventing code execution from data pages. Continuous monitoring of browser update notifications is essential given that such vulnerabilities often remain unpatched in older versions, leaving legacy systems exposed to emerging threats.