CVE-2026-31870

The record

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.1, when a cpp-httplib client uses the streaming API (httplib::stream::Get, httplib::stream::Post, etc.), the library calls std::stoull() directly on the Content-Length header value received from the server with no input validation and no exception handling. std::stoull throws std::invalid_argument for non-numeric strings and std::out_of_range for values exceeding ULLONG_MAX. Since nothing catches these exceptions, the C++ runtime calls std::terminate(), which kills the process with SIGABRT. Any server the client connects to — including servers reached via HTTP redirects, third-party APIs, or man-in-the-middle positions can crash the client application with a single HTTP response. No authentication is required. No interaction from the end user is required. The crash is deterministic and immediate. This vulnerability is fixed in 0.37.1.

Affected packages

Related vulnerabilities

• CVE-2026-100347 kin-openapi is a Go project for handling OpenAPI files. CWE-248
• CVE-2026-102599 Socket.IO enables bidirectional and low-latency communication for every platform. CWE-248
• CVE-2026-107382 MariaDB Connector/Node.js is used to connect applications developed on Node.js to MariaDB… CWE-248
• CVE-2026-106122 The RabbitMQ Java client library allows Java and JVM-based applications to connect to and… CWE-248
• CVE-2026-105757 vLLM is an inference and serving engine for large language models. CWE-248
• CVE-2026-105756 vLLM is an inference and serving engine for large language models. CWE-248
• CVE-2026-103387 A weakness has been identified in garycourt uri-js up to 4.4.1. CWE-248
• CVE-2026-102281 Nest is a framework for building scalable Node.js server-side applications. CWE-248