Vulnerability · Published Oct 14, 2026 · Assigned by GitHub_M
CVE-2026-102944cpp-httplib: Cookie header leaked on cross-origin redirect
High 7.5
In plain English
A high-severity security flaw in cpp-httplib from yhirose. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).
Official description
cpp-httplib is a C++ header-only HTTP/HTTPS library. Prior to 0.51.0, create_redirect_client() removes Host, Proxy-Authorization, and Authorization headers when following a cross-origin 301, 302, 307, or 308 redirect but leaves Cookie headers attached. detail::redirect() copies the request for those redirect codes, so cookies supplied directly or through default_headers_ are sent to the redirect target. An attacker who controls a redirect response, or a network position for a non-HTTPS origin, can receive session cookies intended for the original origin. A 303 redirect is not affected because that path clears all request headers. This issue is fixed in version 0.51.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cpp-httplib | no fix listed | DEBIAN-CVE-2026-102944 |
| Debian:13 | cpp-httplib | no fix listed | DEBIAN-CVE-2026-102944 |
| Debian:14 | cpp-httplib | no fix listed | DEBIAN-CVE-2026-102944 |
| Ubuntu:26.10 | cpp-httplib | no fix listed | UBUNTU-CVE-2026-102944 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| yhirose | cpp-httplib | < 0.51.0 |
Weakness: CWE-522 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N