CVE-2026-16361 in Firefox
Summary
by MITRE • 07/21/2026
Memory safety bugs present in Firefox ESR 115.37 and Firefox ESR 140.12. 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 ESR 115.38 and Firefox ESR 140.13.
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Analysis
by VulDB Data Team • 07/21/2026
This vulnerability represents a critical class of memory safety issues affecting Mozilla Firefox Extended Support Release versions 115.37 and 140.12, where multiple memory safety bugs were identified that could potentially lead to arbitrary code execution. The presence of memory corruption evidence indicates that these flaws exist within the browser's memory management systems, creating opportunities for malicious actors to exploit the underlying software vulnerabilities. These memory safety issues typically arise from improper handling of allocated memory segments, buffer overflows, or use-after-free conditions that can be leveraged by attackers to manipulate program execution flow.
The technical nature of these bugs falls under common vulnerability categories such as CWE-122 Heap-based Buffer Overflow and CWE-416 Use After Free, which are fundamental memory safety concerns that have been extensively documented in cybersecurity literature. The vulnerability landscape for web browsers is particularly treacherous since these applications process untrusted content from multiple sources, making them prime targets for exploitation attempts. The fact that the bugs were present in ESR versions suggests they affected organizations relying on long-term support releases, potentially leaving enterprise environments exposed to sophisticated attack vectors.
From an operational perspective, the impact of these memory safety vulnerabilities extends beyond simple browser instability or crashes. When memory corruption occurs in browser processes, it can enable attackers to execute arbitrary code with the privileges of the user running the browser application. This represents a severe escalation from typical web application vulnerabilities since browsers operate with access to user data, file systems, and network resources. The potential for exploitation increases significantly when considering that these bugs could be triggered through routine browsing activities involving malicious websites or crafted content.
Organizations should prioritize immediate patching of affected Firefox ESR installations to mitigate the identified risks. The fix implemented in versions 115.38 and 140.13 addresses the underlying memory safety issues through enhanced memory management controls and improved input validation mechanisms. Security teams should also consider implementing additional protective measures such as application whitelisting, sandboxing technologies, and network monitoring to detect potential exploitation attempts. The vulnerability aligns with tactics described in the attack framework where adversaries leverage memory corruption vulnerabilities to establish persistent access to target systems, making proactive remediation essential for maintaining security posture.
The presence of these memory safety bugs in ESR releases highlights the importance of maintaining up-to-date software configurations within enterprise environments, particularly when relying on extended support versions that may not receive immediate patches for critical vulnerabilities. Security professionals should monitor patch deployment schedules and consider implementing automated vulnerability management processes to ensure timely remediation of similar issues across their infrastructure.