CVE-2026-117910 in Firefox
Summary
by MITRE • 10/27/2026
Invalid pointer in the JavaScript Engine component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.
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Analysis
by VulDB Data Team • 10/27/2026
The discovery of an invalid pointer issue within the JavaScript engine represents a critical memory safety violation that poses significant risks to browser stability and potential security compromise. In complex software architectures like web browsers, the JavaScript engine is responsible for parsing, compiling, and executing code dynamically. When this component fails to properly validate pointers before dereferencing them or managing their lifecycle, it can lead to undefined behavior within the application's memory space. This specific flaw indicates that under certain conditions, likely triggered by malformed script execution or complex object interactions, the engine attempts to access a memory address that is either unmapped, already freed, or otherwise invalid for the current operation context.
From a technical perspective, this vulnerability aligns closely with CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer and potentially CWE-416 Use After Free if the pointer refers to memory that has been deallocated but not nullified. The root cause typically stems from insufficient checks during garbage collection cycles or JIT compilation processes where references are tracked incorrectly. If an attacker can craft specific JavaScript payloads that exploit this logic error, they may induce a crash resulting in a denial of service against the user's session. More critically, depending on the exact nature of the pointer invalidation and the underlying memory allocator behavior, such errors can sometimes be leveraged to achieve arbitrary code execution by manipulating heap structures or overwriting control flow data.
The operational impact of this vulnerability is severe for end-users who rely on Firefox for browsing untrusted web content. A successful exploitation could allow a remote attacker to crash the browser process, leading to service disruption and potential loss of unsaved work. In more advanced scenarios involving memory corruption, it could facilitate privilege escalation within the sandboxed environment or lead to data exfiltration if adjacent sensitive information resides in nearby memory blocks. This aligns with ATT&CK technique T1203 Exploitation for Client Execution, where attackers use vulnerabilities in client-side software like browsers as an initial access vector after tricking users into visiting malicious sites.
To mitigate the risks associated with this vulnerability, immediate action is required to update affected systems. The issue has been addressed in Firefox version 159 and Firefox Extended Support Release (ESR) version 153.6. Organizations should enforce automated patch management policies to ensure that all endpoints running these browser versions are updated promptly. Additionally, implementing strict content security policies and disabling unnecessary JavaScript features for untrusted sites can reduce the attack surface. Security teams should also monitor for indicators of compromise related to unusual memory usage patterns or frequent browser crashes which might signal attempted exploitation attempts in environments where patching is delayed due to compatibility concerns.