High severity · published Jul 10, 2026
CVE-2026-54919
cpp-httplib: TLS certificate chain verification bypassed for IP-literal hosts on Mbed TLS and wolfSSL backends
7.4
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CP
cpp-httplib · yhirose
>= 0.31.0, < 0.47.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54919
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54919
Patch
https://github.com/yhirose/cpp-httplib/commit/fa981cedae004ea9d946f1392b9dec22fac6fee6
Product
https://github.com/yhirose/cpp-httplib/releases/tag/v0.47.0
Mitigation
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-8ffh-4p95-g3p2
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