Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34441cpp-httplib: HTTP Request Smuggling via Unconsumed GET Request Body
Medium 4.8
In plain English
A medium-severity security flaw in cpp-httplib from yhirose. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cpp-httplib | no fix listed | DEBIAN-CVE-2026-34441 |
| Debian:13 | cpp-httplib | no fix listed | DEBIAN-CVE-2026-34441 |
| Debian:14 | cpp-httplib | 0.41.0+ds-3 | DEBIAN-CVE-2026-34441 |
| Ubuntu:25.10 | cpp-httplib | no fix listed | UBUNTU-CVE-2026-34441 |
| Ubuntu:26.10 | cpp-httplib | no fix listed | UBUNTU-CVE-2026-34441 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| yhirose | cpp-httplib | < 0.40.0 |
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
References
- https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-jv63-rm9j-6jwc x_refsource_CONFIRM
- https://github.com/yhirose/cpp-httplib/releases/tag/v0.40.0 x_refsource_MISC