PT-2026-24759 · Unknown · Cpp-Httplib

0X3Xploit

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Published

2026-03-11

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Updated

2026-03-21

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CVE-2026-31870

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions cpp-httplib versions prior to 0.37.1
Description cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. When using the streaming API (httplib::stream::Get, httplib::stream::Post, etc.), the library directly calls std::stoull() on the Content-Length header value received from a server without input validation or exception handling. std::stoull() throws std::invalid argument for non-numeric strings and std::out of range for values exceeding ULLONG MAX. Because these exceptions are not handled, the C++ runtime calls std::terminate(), terminating the process with SIGABRT. Any server the client connects to—including those reached via HTTP redirects or through man-in-the-middle positions—can crash the client application with a single HTTP response. No authentication or user interaction is required, and the crash is deterministic and immediate.
Recommendations Versions prior to 0.37.1 should be updated to version 0.37.1 or later.

Exploit

Fix

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Weakness Enumeration

Related Identifiers

CVE-2026-31870
GHSA-39Q5-HH6X-JPXX
OESA-2026-1637
OESA-2026-1638
OESA-2026-1639
OESA-2026-1640

Affected Products

Cpp-Httplib