CVE-2026-102944 cpp-httplib: Cookie header leaked on cross-origin redirect
Attackers can steal session cookies via cross-origin redirects in cpp-httplib due to missing header sanitization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-102944?
CVE-2026-102944 is a high-severity vulnerability in yhirose cpp-httplib, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-522
Which versions are affected by CVE-2026-102944?
How do I fix CVE-2026-102944?
Upgrade to a fixed version.
Is CVE-2026-102944 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-102944 exists.
Sources
Also known as DEBIAN-CVE-2026-102944, GHSA-22mf-w2v3-r2jv, OESA-2026-4521, OESA-2026-4522, OESA-2026-4523, OESA-2026-4524 and 1 more.