NULL Pointer Dereference Affecting cpp-httplib package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.49% (40th percentile)

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  • Snyk IDSNYK-ECHOLATEST-CPPHTTPLIB-19401943
  • published28 Aug 2026
  • disclosed29 May 2026

Introduced: 29 May 2026

CVE-2026-46527  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest cpp-httplib.

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 Echo. See How to fix? for Echo:latest relevant fixed versions and status.

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, When the server has called Server::set_trusted_proxies() with a non-empty trusted-proxy list, an attacker can send an HTTP request that includes an X-Forwarded-For header whose value parses to no valid IP segments. The code path then executes get_client_ip(), which calls front() on an empty std::vector—undefined behavior in C++. On typical implementations this manifests as abnormal process termination (denial of service). With Sanitizers enabled, you get an explicit runtime diagnostic. This vulnerability is fixed in 0.44.0.

CVSS Base Scores

version 3.1