CVE-2026-16352 in Firefox
Summary
by MITRE • 07/21/2026
Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
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Analysis
by VulDB Data Team • 07/21/2026
The vulnerability under discussion represents a critical sandbox escape flaw originating from a use-after-free condition within the Disability Access APIs component of the firefox browser. This particular weakness allows malicious actors to potentially bypass security boundaries that are fundamental to protecting users from harmful code execution. The Disability Access APIs serve as an interface for assistive technologies to interact with the browser, providing accessibility features such as screen readers and keyboard navigation support. When this component fails to properly manage memory allocation and deallocation, it creates opportunities for attackers to manipulate freed memory regions and execute arbitrary code outside of the intended sandbox environment.
The technical nature of this vulnerability aligns with common software security patterns where improper memory management leads to exploitable conditions. The use-after-free flaw occurs when a program continues to reference memory that has already been freed, potentially allowing an attacker to control the memory layout and redirect execution flow. This particular implementation resides within firefox's accessibility subsystem, which typically operates with elevated privileges due to its role in enabling assistive technologies for users with disabilities. The attack surface becomes particularly dangerous because this component often requires privileged access to system resources while maintaining a level of trust that may not exist in the standard browsing context.
The operational impact of this vulnerability extends beyond simple privilege escalation as it fundamentally undermines firefox's security model and sandboxing mechanisms. When an attacker successfully exploits this use-after-free condition, they can potentially execute code with the same privileges as the assistive technology processes, which often have extensive system access rights. This creates a pathway for attackers to bypass multiple layers of security controls that are designed to isolate browser processes from the underlying operating system. The vulnerability affects multiple firefox release channels including the standard Firefox 153, Extended Support Release 115.38, and Extended Support Release 140.13, indicating that this flaw impacted a broad user base across different firefox deployment scenarios.
This vulnerability type corresponds to CWE-416 which specifically addresses use-after-free conditions in software implementations. The attack pattern aligns with techniques described in the ATT&CK framework under privilege escalation and defense evasion tactics, where adversaries leverage memory corruption vulnerabilities to gain unauthorized access to system resources. The fix implemented by mozilla involves proper memory management practices that ensure objects are not accessed after being freed, along with additional validation checks within the accessibility APIs. These mitigations prevent attackers from manipulating freed memory regions while maintaining the intended functionality of assistive technologies.
The remediation approach taken by firefox developers demonstrates the importance of comprehensive security testing for components that interface with system-level resources. The vulnerability highlights the need for rigorous memory management practices in accessibility frameworks where code execution privileges may be elevated. Security researchers and organizations implementing firefox in enterprise environments should prioritize updating to the patched versions as this flaw could enable sophisticated attacks targeting users who rely on accessibility features. The fix represents a standard approach to addressing use-after-free vulnerabilities through proper resource deallocation and validation, which is consistent with industry best practices for preventing memory corruption exploits.