VULNERABILITY INTELLIGENCE

CVE-2026-28434

CVSS score5.3 MEDIUM
EPSS probability0.35%
CISA KEVNot currently listed
Published2026-03-04
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Description

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.

Weakness classification

  • security-advisories@github.com: CWE-200
  • nvd@nist.gov: NVD-CWE-noinfo

Primary references