CVE-2026-118563 in CacheFlush
Summary
by MITRE • 10/30/2026
Vulnerability in Drupal CacheFlush. This issue affects CacheFlush versions: *.*.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified within the Drupal module known as CacheFlush represents a significant security risk associated with improper handling of cache invalidation mechanisms. The affected software encompasses all version numbers, indicating that every release of this specific module is susceptible to exploitation due to fundamental architectural flaws in how it processes requests intended to clear cached data. In web application architectures like Drupal, caching layers are critical for performance optimization by storing frequently accessed content and reducing database load. However, when the mechanisms responsible for flushing or invalidating these caches are not rigorously validated against malicious input, they can become vectors for various attacks including unauthorized access, denial of service, or even remote code execution depending on the underlying implementation details.
From a technical perspective, this flaw likely stems from insufficient validation of user-supplied data passed to cache clearing functions. In many content management systems, administrative actions such as flushing caches require elevated privileges and often involve direct interaction with system files or database tables. If an attacker can manipulate parameters sent to these endpoints without proper authentication checks or input sanitization, they may trigger unintended side effects. For instance, if the module fails to verify that the request originates from a legitimate administrator session, it could allow unauthenticated users to execute cache-clearing operations repeatedly. This lack of access control is a classic example of broken object level authorization where the application does not properly enforce policy regarding which actors can perform specific actions on system resources.
The operational impact of this vulnerability extends beyond simple performance degradation or service interruption. An attacker exploiting this flaw could potentially cause a denial of service by overwhelming server resources through rapid, repeated cache flush requests. More critically, depending on how the underlying Drupal core handles these operations, there may be pathways to achieve remote code execution if the module interacts with file systems in an unsafe manner during the cleanup process. This aligns closely with CWE-20 Improper Input Validation and CWE-862 Missing Authorization, which are common root causes for such issues in web applications. The absence of robust input validation allows attackers to inject malicious payloads or manipulate internal states that were not intended to be modified by external users.
Furthermore, the persistence of this vulnerability across all versions suggests a systemic design flaw rather than an isolated coding error introduced in a specific release cycle. This implies that previous attempts at mitigation may have been superficial or focused on edge cases while ignoring the core logic governing cache management. Security researchers and developers must recognize that caching modules often operate with high privileges because they need to modify critical system states. Therefore, any weakness in their implementation poses an elevated risk profile compared to standard content display vulnerabilities. The ATT&CK framework categorizes such behaviors under techniques involving resource hijacking or impact via denial of service, highlighting the potential for attackers to disrupt business continuity by targeting these infrastructure components.
To mitigate this vulnerability, immediate action is required to either patch the module if a fixed version becomes available or disable it entirely until proper remediation can be implemented. Administrators should audit their Drupal installations for any usage of CacheFlush and remove dependencies on it where possible. Implementing strict access controls using web application firewalls can help block malicious requests targeting cache endpoints before they reach the application logic. Additionally, enforcing principle of least privilege ensures that only authenticated administrators with verified sessions can interact with sensitive system functions. Regular security audits and static code analysis focused on input validation and authorization checks are essential to prevent similar flaws in future developments or other modules within the ecosystem.