CVE-2026-32627 cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy
Attackers can intercept HTTPS traffic by exploiting a TLS verification bypass during redirects in cpp-httplib clients using proxies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32627?
CVE-2026-32627 is a high-severity vulnerability in yhirose cpp-httplib, published on 13 Mar 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++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.2, when a cpp-httplib client is configured with a proxy and set_follow_location(true), any HTTPS redirect it follows will have TLS certificate and hostname verification silently disabled on the new connection. The client will accept any certificate presented by the redirect target — expired, self-signed, or forged — without raising an error or notifying the application. A network attacker in a position to return a redirect response can fully intercept the follow-up HTTPS connection, including any credentials or session tokens in flight. This vulnerability is fixed in 0.37.2.
Weakness: CWE-295
Which versions are affected by CVE-2026-32627?
It affects 1 product.
Products include Yhirose Cpp-Httplib.
How do I fix CVE-2026-32627?
Upgrade to a fixed version.
Is CVE-2026-32627 being exploited?
There is no known exploitation of CVE-2026-32627 in the wild and no public exploit code.
Other vulnerabilities in yhirose cpp-httplib
- CVE-2025-66570 cpp-httplib Untrusted HTTP Header Handling: Internal Header Shadowing (REMOTE*/LOCAL*)
- CVE-2026-45372 cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection
- CVE-2026-46527 Null dereference in cpp-httplib
- CVE-2026-22776 cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb
- CVE-2026-21428 cpp-httplib has CRLF injection in http headers
Sources
Also known as DEBIAN-CVE-2026-32627, GHSA-c3h8-fqq4-xm4g, UBUNTU-CVE-2026-32627.