Information Exposure Affecting cpp-httplib package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.43% (35th percentile)

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  • Snyk IDSNYK-ECHOLATEST-CPPHTTPLIB-19401934
  • published28 Aug 2026
  • disclosed4 Mar 2026

Introduced: 4 Mar 2026

CVE-2026-28434  (opens in a new tab)
CWE-200  (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 0.35.0, when a request handler throws a C++ exception and the application has not registered a custom exception handler via set_exception_handler(), the library catches the exception and writes its message directly into the HTTP response as a header named EXCEPTION_WHAT. This header is sent to whoever made the request, with no authentication check and no special configuration required to trigger it. The behavior is on by default. A developer who does not know to opt in to set_exception_handler() will ship a server that leaks internal exception messages to any client. This vulnerability is fixed in 0.35.0.

CVSS Base Scores

version 3.1