CVE-2026-54919 cpp-httplib: TLS certificate chain verification bypassed for IP-literal hosts on Mbed TLS and wolfSSL backends
Man-in-the-middle attackers can bypass TLS certificate verification for IP-literal hosts in specific backends, allowing traffic interception and modification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-54919?
CVE-2026-54919 is a high-severity vulnerability in yhirose cpp-httplib, published on 10 Jul 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. In affected Mbed TLS backend versions from 0.31.0 through 0.46.1 and wolfSSL backend versions from 0.33.0 through 0.46.1, when cpp-httplib is built with CPPHTTPLIB_MBEDTLS_SUPPORT or CPPHTTPLIB_WOLFSSL_SUPPORT and a client connects to an IP-literal host with server certificate verification enabled, SSLClient and Client in HTTPS mode skip certificate chain validation and WebSocketClient on the Mbed TLS backend skips verification altogether, allowing a man-in-the-middle attacker positioned to intercept traffic to present a crafted certificate and read or modify the traffic. This issue is fixed in version 0.47.0.
Weakness: CWE-295
Which versions are affected by CVE-2026-54919?
It affects 1 product.
Products include Yhirose Cpp-Httplib.
How do I fix CVE-2026-54919?
No fix has been published for CVE-2026-54919 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-54919 being exploited?
There is no known exploitation of CVE-2026-54919 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-2026-32627 cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy
- CVE-2026-22776 cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb
Sources
Also known as DEBIAN-CVE-2026-54919, GHSA-8ffh-4p95-g3p2, UBUNTU-CVE-2026-54919.