CVE-2026-92008 in Firefox
Summary
by MITRE • 09/15/2026
Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.
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Analysis
by VulDB Data Team • 09/16/2026
The identified security flaw resides within the CanvasWebGL component of Mozilla Firefox, specifically involving incorrect boundary conditions that facilitate privilege escalation. This vulnerability stems from a failure in the software to properly validate input parameters or memory indices when processing WebGL operations. In complex graphics rendering pipelines, such as those utilized by WebGPU and WebGL contexts, precise handling of array bounds is critical for maintaining system integrity. When these boundaries are not strictly enforced, an attacker can craft malicious web content that triggers out-of-bounds reads or writes within the browser's process space. This mismanagement allows data to be read from or written to memory locations outside the intended scope, bypassing standard sandbox restrictions designed to isolate untrusted web content from sensitive system resources and user data.
From a technical perspective, this issue classifies as an out-of-bounds access vulnerability, aligning with Common Weakness Enumeration identifier CWE-125 for Out-of-Bounds Read or CWE-787 for Out-of-Bounds Write depending on the specific nature of the memory corruption exploited. The root cause lies in the graphics subsystem's handling of vertex buffers, texture coordinates, or shader inputs where boundary checks are either missing or incorrectly implemented. By manipulating these parameters through JavaScript APIs exposed to web pages, a malicious actor can induce undefined behavior within the browser engine. This often leads to arbitrary code execution capabilities if the memory corruption allows for control over instruction pointers or function return addresses, effectively elevating privileges from the restricted sandboxed context of the tab process to higher-privilege processes such as the GPU process or even the main browser process.
The operational impact of this vulnerability is severe due to its potential for remote code execution via a web page. An attacker could host a specially crafted website that exploits these boundary condition errors when rendered in Firefox. Upon visiting the site, the malicious script would trigger the flawed WebGL operations, leading to memory corruption and subsequent privilege escalation. This compromises the fundamental security model of modern browsers, which relies on strict isolation between tabs and system components. Successful exploitation allows an attacker to bypass sandbox protections, potentially accessing sensitive user data such as cookies, session tokens, passwords stored in password managers, or other confidential information residing in higher-privileged memory spaces. It also enables further lateral movement within the victim's environment by executing arbitrary code with elevated privileges.
This vulnerability maps directly to MITRE ATT&CK techniques related to privilege escalation and sandbox escape. Specifically, it aligns with T1068 Exploitation for Privilege Escalation and potentially T1211 Exploitation for Defense Evasion if used to bypass security controls. The attack vector is classified as Network-based (T1190) since the exploitation occurs through a web page accessed via standard HTTP or HTTPS protocols, requiring no prior access to the target system other than convincing the user to visit a malicious site.
To mitigate this risk, users must ensure they are running patched versions of Firefox that include fixes for these boundary condition checks. The vulnerability has been addressed in Firefox version 156 and extended support release (ESR) branches including ESR 115.41, ESR 140.16, and ESR 153.3. Organizations should enforce automatic updates or implement patch management policies to ensure all endpoints are running these secure versions. Additionally, deploying browser hardening solutions such as content security policy implementations where applicable can help restrict the execution of potentially malicious scripts. Security teams should also monitor for indicators of compromise associated with WebGL exploitation attempts and consider restricting WebGL access in high-security environments if feasible through enterprise configuration profiles.