CVE-2026-34441 | yhirose cpp-httplib up to 0.39.x HTTP Request request smuggling (GHSA-jv63-rm9j-6jwc)

VDB-354581 · CVE-2026-34441 · GHSA-JV63-RM9J-6JWC YHIROSE CPP-HTTPLIB UP TO 0.39.X HTTP REQUEST REQUEST SMUGGLING HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.1 $0-$5k 1.65+ Summaryinfo A vulnerability has been found in yhirose cpp-httplib up to 0.39.x and classified as problematic. The impacted element is an unknown function of the component HTTP Request Handler. The manipulation leads to request smuggling. This vulnerability is documented as CVE-2026-34441. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded. Detailsinfo A vulnerability was found in yhirose cpp-httplib up to 0.39.x. It has been rated as problematic. This issue affects an unknown part of the component HTTP Request Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. Impacted is confidentiality, integrity, and availability. The summary by CVE is: cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread body bytes remain on the TCP stream and are interpreted as the start of a new HTTP request. An attacker can embed an arbitrary HTTP request inside the body of a GET request, which the server processes as a separate request. This issue has been patched in version 0.40.0. The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-34441 since 03/27/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. Upgrading to version 0.40.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. 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 0.39 Website Product: https://github.com/yhirose/cpp-httplib/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 5.2 VulDB Meta Temp Score: 5.1 VulDB Base Score: 5.6 VulDB Temp Score: 5.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 4.8 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Request smuggling CWE: CWE-444 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: cpp-httplib 0.40.0 Timelineinfo 03/27/2026 CVE reserved 04/01/2026 +4 days Advisory disclosed 04/01/2026 +0 days VulDB entry created 04/01/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-jv63-rm9j-6jwc Status: Confirmed CVE: CVE-2026-34441 (🔒) GCVE (CVE): GCVE-0-2026-34441 GCVE (VulDB): GCVE-100-354581 Entryinfo Created: 04/01/2026 04:28 Changes: 04/01/2026 04:28 (65) Complete: 🔍 Cache ID: 99:3A0:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸