CVE-2026-28434

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 v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/yhirose/cpp-httplib/commit/defd907c7469c5c8281247b73bbd07be24c31164	Patch
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-8mpw-r4gc-xm7q	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-03-04 20:16

Updated : 2026-03-05 22:11

NVD link : CVE-2026-28434

Mitre link : CVE-2026-28434

CVE.ORG link : CVE-2026-28434

JSON object : View

Products Affected

yhirose

cpp-httplib

CWE

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

NVD-CWE-noinfo

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