CVE-2026-16360 in Firefox
Summary
by MITRE • 07/21/2026
Memory safety bugs present in Firefox ESR 115.37, Firefox ESR 140.12 and Firefox 152. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. 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
This vulnerability represents a collection of memory safety issues discovered in Mozilla Firefox browser versions, specifically affecting the extended support release branches 115.37 and 140.12 along with the mainline Firefox 152 release. The presence of memory corruption evidence within these bugs indicates fundamental flaws in how the browser handles memory allocation and deallocation processes, creating potential entry points for malicious actors seeking to compromise system security. These vulnerabilities fall under the broader category of memory safety issues that have been extensively documented in cybersecurity literature and are commonly associated with remote code execution exploits.
The technical nature of these memory safety bugs stems from improper handling of memory operations within Firefox's rendering engine and JavaScript interpreter components. Such flaws typically manifest as buffer overflows, use-after-free conditions, or double-free errors that occur when the browser attempts to manage memory resources for web content processing. When these conditions are triggered through malicious web pages or crafted inputs, they can corrupt memory layout and potentially allow attackers to manipulate program execution flow. The vulnerability classification aligns with common CWE entries such as CWE-121 for heap-based buffer overflow and CWE-416 for use-after-free conditions, which are frequently exploited in browser-based attacks.
The operational impact of these vulnerabilities extends beyond simple browser instability, as they represent serious security risks that could enable attackers to execute arbitrary code on affected systems. This capability would allow threat actors to perform actions such as installing malware, stealing sensitive data, or establishing persistent access to compromised machines. The fact that multiple versions were affected indicates a systemic issue within Firefox's memory management subsystem that required comprehensive patching across different release channels. Attackers could potentially exploit these vulnerabilities through drive-by downloads or malicious websites without requiring user interaction beyond visiting compromised pages.
Mitigation strategies for this vulnerability require immediate deployment of the security patches released in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13 versions. Organizations should prioritize updating all affected browser installations to prevent exploitation attempts, as these vulnerabilities are likely candidates for inclusion in exploit kits targeting unpatched systems. Security teams should also implement network monitoring to detect potential exploitation attempts through unusual traffic patterns or known malicious indicators associated with these memory corruption exploits. The remediation approach aligns with ATT&CK framework techniques such as T1059 for command and scripting interpreter and T1203 for exploitation for client execution, emphasizing the need for layered defensive measures including browser hardening, network segmentation, and user education about safe browsing practices.
The presence of these memory safety issues in Firefox demonstrates the ongoing challenge faced by browser vendors in maintaining secure codebases while delivering complex web platform features. These vulnerabilities highlight the critical importance of thorough security testing, code review processes, and automated memory checking tools such as AddressSanitizer and UndefinedBehaviorSanitizer that can detect similar issues during development cycles. The exploitation potential of these bugs underscores the necessity for organizations to maintain up-to-date security patches and implement robust vulnerability management programs to address similar issues across their technology infrastructure.