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CVE-2026-31870

CVE-2026-31870 · cpp-httplib Affected by Remote Process Crash via Malformed Content-Length Response Header

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 0.5% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • cpp-httplib

    Versions
    • < 0.37.1: Affected

    No fix published

  • cpp-httplib Debian:12

    Versions
    • 0.11.4+ds-1
    • 0.11.4+ds-1+deb12u1
    • 0.11.4+ds-2
    • 0.11.4+ds-3
    • 0.13.1+ds-1
    • 0.14.0+ds-1
    • 0.14.1+ds-1
    • 0.14.1+ds-2
    • 0.14.2+ds-1
    • 0.14.3+ds-1
    • 0.14.3+ds-1.1
    • 0.14.3+ds-1.1~exp1
    • 0.15.3+ds-1
    • 0.15.3+ds-2
    • 0.15.3+ds-3
    • 0.16.0+ds-1
    • 0.16.3+ds-1
    • 0.16.3+ds-2
    • 0.18.0+ds-1
    • 0.18.7-1
    • 0.20.1+ds-3
    • 0.25.0+ds-1
    • 0.26.0+ds-2
    • 0.41.0+ds-1
    • 0.41.0+ds-2
    • 0.41.0+ds-3
    • 0.41.0+ds-3~bpo13+1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Debian:13

    Versions
    • 0.18.7-1
    • 0.18.7-1+deb13u1
    • 0.20.1+ds-3
    • 0.25.0+ds-1
    • 0.26.0+ds-2
    • 0.41.0+ds-1
    • 0.41.0+ds-2
    • 0.41.0+ds-3
    • 0.41.0+ds-3~bpo13+1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Debian:14

    Versions
    • 0.18.7-1
    • 0.20.1+ds-3
    • 0.25.0+ds-1
    • 0.26.0+ds-2
    • 0.41.0+ds-1
    • 0.41.0+ds-2
    • 0.41.0+ds-3~bpo13+1
    Affected ranges
    • ECOSYSTEM: < 0.41.0+ds-3

    Update to 0.41.0+ds-3

  • cpp-httplib Ubuntu:Pro:22.04:LTS

    Versions
    • 0.9.9+ds-1
    • 0.9.10+ds-1
    • 0.10.1+ds-1
    • 0.10.2+ds-1
    • 0.10.3+ds-1
    • 0.10.3+ds-1ubuntu0.1~esm1
    • 0.10.3+ds-1ubuntu0.1~esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Ubuntu:Pro:24.04:LTS

    Versions
    • 0.13.1+ds-1ubuntu1
    • 0.14.3+ds-1
    • 0.14.3+ds-1.1
    • 0.14.3+ds-1.1build1
    • 0.14.3+ds-1.1build2
    • 0.14.3+ds-1.1ubuntu0.1~esm1
    • 0.14.3+ds-1.1ubuntu0.1~esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Ubuntu:25.10

    Versions
    • 0.18.7-1
    • 0.18.7-1ubuntu0.25.10.1
    • 0.18.7-1ubuntu0.25.10.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Ubuntu:26.10

    Versions
    • 0.26.0+ds-2ubuntu3
    • 0.26.0+ds-2ubuntu4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • cpp-httplib Ubuntu:Pro:26.04:LTS

    Versions
    • 0.18.7-1
    • 0.26.0+ds-2ubuntu2
    • 0.26.0+ds-2ubuntu3
    • 0.26.0+ds-2ubuntu3+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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