CVE-2026-67183 in TinyWeb
Summary
by MITRE • 07/28/2026
TinyWeb through 0.0.8 contains a memory leak vulnerability that allows unauthenticated attackers to exhaust available memory by sending ordinary well-formed HTTP requests. Each request causes HttpParser::execute() to allocate Url objects, HttpHeaders objects, and HttpHeader instances via raw new expressions that are never freed due to missing destructors and unreachable delete calls, causing worker resident memory to grow monotonically by approximately 20 to 28 kB per request until the worker process is killed.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability in TinyWeb version 0.0.8 represents a critical memory management flaw that enables denial of service attacks through simple HTTP requests. The issue stems from improper resource cleanup within the HTTP parsing component where HttpParser::execute() function continuously allocates Url objects, HttpHeaders objects, and HttpHeader instances without subsequent deallocation. The root cause lies in the absence of proper destructors for these allocated objects and unreachable delete calls that would normally free the memory. This memory leak manifests as a gradual increase in worker process resident memory consumption, with each HTTP request contributing approximately 20 to 28 kilobytes of additional memory usage that accumulates over time.
The operational impact of this vulnerability is severe as it allows unauthenticated attackers to systematically exhaust system resources without requiring any special privileges or complex attack vectors. The vulnerability operates through ordinary well-formed HTTP requests, making it particularly dangerous because it can be exploited using standard network tools and does not require sophisticated attack techniques. As the worker processes continue to allocate memory without freeing it, the memory consumption grows monotonically until the process eventually crashes or becomes unresponsive due to resource exhaustion. This creates a persistent denial of service condition that can affect legitimate users and applications relying on the web server functionality.
From a cybersecurity perspective, this vulnerability aligns with CWE-401 Memory Leak, which specifically addresses situations where allocated memory is not properly freed, leading to gradual resource depletion. The attack pattern follows ATT&CK technique T1499.004 Network Denial of Service, as it targets network resources through memory exhaustion attacks that render services unavailable to legitimate users. The vulnerability demonstrates poor software engineering practices in memory management and highlights the importance of proper RAII (Resource Acquisition Is Initialization) principles in C++ applications. The lack of automatic cleanup mechanisms and the manual memory management approach creates a dangerous situation where resource leaks accumulate over time, eventually compromising system stability and availability.
The most effective mitigation strategy involves implementing proper destructors for all allocated objects and ensuring that all dynamically allocated memory is properly deallocated through either automatic cleanup mechanisms or explicit deletion calls. The code should be reviewed to identify all new allocations and ensure corresponding delete operations are either automatically handled through smart pointers or explicitly called in destructor methods. Additionally, implementing memory monitoring and resource limits can help detect and prevent excessive memory consumption, while regular code audits should verify that all allocated resources have proper cleanup procedures. The fix requires careful attention to the HttpParser::execute() function's object lifetime management to ensure that Url objects, HttpHeaders objects, and HttpHeader instances are properly destroyed when no longer needed, preventing the cumulative memory growth observed in this vulnerability.