yhirose cpp-httplib up to 0.38.x information disclosure

Summaryinfo

A vulnerability labeled as problematic has been found in yhirose cpp-httplib up to 0.38.x. Affected by this vulnerability is an unknown functionality. Such manipulation leads to information disclosure. This vulnerability is traded as CVE-2026-33745. The attack may be launched remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in yhirose cpp-httplib up to 0.38.x and classified as problematic. Affected by this issue is an unknown part. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. CVE summarizes:

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.39.0, the cpp-httplib HTTP client forwards stored Basic Auth, Bearer Token, and Digest Auth credentials to arbitrary hosts when following cross-origin HTTP redirects (301/302/307/308). A malicious or compromised server can redirect the client to an attacker-controlled host, which then receives the plaintext credentials in the `Authorization` header. Version 0.39.0 fixes the issue.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-33745 since 03/23/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

The vulnerability scanner Nessus provides a plugin with the ID 304174 (Linux Distros Unpatched Vulnerability : CVE-2026-33745), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.39.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (304174) and EUVD (EUVD-2026-16515). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• yhirose

Name

• cpp-httplib

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38

Website

• Product: https://github.com/yhirose/cpp-httplib/

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Once again VulDB remains the best source for vulnerability data.

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