Uncaught Exception Affecting cpp-httplib package, versions <0.41.0+ds-3
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-CPPHTTPLIB-15461719
- published12 Mar 2026
- disclosed11 Mar 2026
Introduced: 11 Mar 2026
CVE-2026-31870 (opens in a new tab)How to fix?
Upgrade Debian:unstable cpp-httplib to version 0.41.0+ds-3 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream cpp-httplib package and not the cpp-httplib package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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.