CVE-2026-92016 in Firefox
Summary
by MITRE • 09/15/2026
Use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 156, Firefox ESR 140.16, and Firefox ESR 153.3.
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Analysis
by VulDB Data Team • 09/15/2026
The identified vulnerability represents a critical memory management error classified as an out-of-bounds write resulting from use-after-free conditions within the Disability Access APIs component of Mozilla Firefox. This specific class of flaw occurs when the application attempts to access or manipulate memory that has already been deallocated by the system, leading to undefined behavior and potential security breaches. In the context of browser architecture, such vulnerabilities are particularly dangerous because they reside in components responsible for accessibility features, which often maintain persistent state and complex object lifecycles involving multiple threads and asynchronous operations. The root cause typically involves a race condition or improper reference counting where an object is freed while still being referenced by another part of the application logic, allowing an attacker to control the contents of that memory region before it is reallocated for other purposes.
From a technical perspective, this vulnerability falls under CWE-416 which denotes Use After Free, and often intersects with CWE-787 Out-of-bounds Write when the freed memory is reused in a way that allows writing beyond intended boundaries. The operational impact of such a flaw extends far beyond simple application crashes or denial of service scenarios. An attacker who can trigger this vulnerability through malicious web content could potentially achieve arbitrary code execution on the victim's machine by carefully crafting heap layouts and exploiting the window between deallocation and reallocation to inject shellcode or redirect control flow. This capability effectively bypasses many modern browser security mitigations such as ASLR and DEP, providing a direct path for full system compromise if combined with other exploitation techniques like sandbox escapes.
The vulnerability was addressed in Firefox version 156, as well as the extended support releases ESR 140.16 and ESR 153.3, indicating that Mozilla prioritized this fix due to its severity and prevalence in accessibility-related code paths. These updates likely involved rigorous refactoring of memory management practices within the Disability Access APIs, ensuring proper synchronization between object lifecycles and preventing access to freed pointers. For organizations relying on these browsers for enterprise environments or public-facing services, immediate patching is essential to mitigate the risk of remote code execution attacks targeting users with accessibility needs enabled. Security teams should verify that all endpoints running affected versions are updated promptly and consider implementing network-level controls such as content security policies to limit the impact if a similar vulnerability were discovered in unpatched systems before remediation can occur.