CVE-2026-92078 in Firefox
Summary
by MITRE • 09/15/2026
Denial-of-service in the Security component. This vulnerability was fixed in Firefox 156 and Firefox ESR 153.3.
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Analysis
by VulDB Data Team • 09/15/2026
The identified security issue represents a denial of service condition located within the core security components of Mozilla Firefox, specifically affecting versions prior to 156 and Firefox Extended Support Release version 153.3. Denial of service vulnerabilities in browser engines are particularly critical because they can be triggered by maliciously crafted web content or network interactions that force the application into an unrecoverable state without necessarily compromising user data confidentiality or integrity directly. In this specific instance, the flaw likely stems from improper handling of resources during security-related operations such as certificate validation, secure connection negotiation, or memory management within the TLS stack or related cryptographic modules. When a remote attacker triggers this condition through specially designed HTTP requests or SSL/TLS handshakes, it causes the browser process to crash or become unresponsive, effectively denying service to legitimate users attempting to access affected websites or perform secure communications.
From a technical perspective, such vulnerabilities often arise from race conditions, buffer overflows that do not lead to code execution but cause memory corruption leading to crashes, or infinite loops triggered by malformed input data processed during security checks. The impact of this vulnerability is primarily operational rather than exploitative for remote code execution. Users experiencing the flaw may find their browser freezing completely upon visiting specific sites or interacting with certain secure elements, requiring a forced restart of the application. This disrupts productivity and can be leveraged in targeted attacks to degrade user experience or potentially facilitate other social engineering tactics by making security warnings appear unreliable due to frequent crashes. The vulnerability aligns with CWE-400, which covers uncontrolled resource consumption leading to denial of service conditions, and may also relate to CWE-787 if the crash is caused by a write-outside-bounds scenario that does not permit arbitrary code execution but destabilizes the process memory space.
In terms of threat modeling, this vulnerability maps to MITRE ATT&CK technique T1499, Endpoint Denial of Service, specifically under sub-techniques involving application exhaustion or resource loopjacking if the flaw involves infinite loops consuming CPU cycles. It also relates to T1053, Scheduled Task/Job, only insofar as it affects system stability during routine browsing activities which are often automated by scripts or bots that might exploit this crash behavior to disrupt monitoring systems relying on browser-based interfaces. The severity is generally classified as medium because while the availability of the software is compromised, there is no direct path to privilege escalation or data exfiltration through this specific vector alone. However, in environments where Firefox is used for sensitive operations such as online banking or corporate intranet access, even a denial of service can have significant business continuity implications.
Mitigation strategies focus primarily on timely patching and configuration hardening. The definitive resolution involves upgrading to Mozilla Firefox version 156 or the Extended Support Release version 153.3 where these security components have been patched with proper input validation and resource management checks. Organizations should enforce automated update policies to ensure all endpoints are running supported versions of the browser. Additionally, deploying network-level protections such as Web Application Firewalls can help filter out malformed requests that trigger this vulnerability before they reach the client application. For users unable to upgrade immediately due to compatibility constraints with legacy internal applications, implementing strict content security policies and disabling unnecessary plugins or extensions may reduce the attack surface by limiting the types of scripts and resources processed during secure connections. Regular monitoring for unusual browser behavior or frequent crashes can also serve as an early detection mechanism for exploitation attempts in real-time environments.