CVE-2026-92024 in Firefox
Summary
by MITRE • 09/15/2026
Use-after-free in the SVG 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 • 09/15/2026
The identified vulnerability represents a critical memory management error classified as an out-of-bounds write resulting from a use-after-free condition within the Scalable Vector Graphics rendering engine of Mozilla Firefox browsers. This specific flaw occurs when the application continues to reference a block of memory that has already been deallocated, leading to undefined behavior during the parsing and rendering of SVG content. Such vulnerabilities are typically categorized under CWE-416 in the Common Weakness Enumeration framework, which highlights the danger of accessing freed memory regions without proper validation or reallocation checks. The technical root cause lies in the lifecycle management of internal objects used for drawing vector paths; if an object is destroyed while still being referenced by a pending rendering operation or event handler, subsequent access to that object results in writing data into arbitrary memory locations controlled by the attacker through crafted SVG input.
The operational impact of this vulnerability extends beyond simple application instability, as it poses a significant risk to system security and integrity. By exploiting the use-after-free condition, an attacker can potentially achieve arbitrary code execution on the victim's machine with the privileges of the user running the browser. This is particularly dangerous in web contexts where users may inadvertently visit maliciously crafted websites containing specially designed SVG files. The ability to write to arbitrary memory allows for heap spraying techniques or control flow hijacking, which are standard methodologies employed by malware authors and advanced persistent threat groups to establish footholds within enterprise environments. Furthermore, this flaw aligns with ATT&CK technique T1203, which covers exploitation of client software vulnerabilities, indicating that it can be leveraged in drive-by download attacks without requiring user interaction beyond visiting the compromised webpage.
Mitigation strategies for this vulnerability primarily rely on applying the vendor-provided patches released to address the memory management logic errors within the SVG component. Users and system administrators must ensure that all instances of Firefox are updated to version 156, or specifically to Firefox ESR versions 115.41, 140.16, and 153.3 as appropriate for their deployment environment. For organizations unable to immediately patch due to compatibility constraints, implementing network-level filtering rules that block access to untrusted domains hosting dynamic SVG content can provide a temporary layer of defense. Additionally, enabling strict Content Security Policy headers on internal web applications reduces the attack surface by restricting the types of resources that can be loaded and executed within the browser context. Regular security audits and penetration testing focused on input validation in rich media components are recommended to identify similar memory safety issues before they can be exploited in production environments.