Is CVE-2026-54919 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-54919 being exploited in the wild.

How severe is CVE-2026-54919?

High severity, with a CVSS score of 7.4, published 10 July 2026.

Which products and versions are affected?

Yhirose Httplib 0.31.0 - 0.46.1.

Is there a fix for CVE-2026-54919?

A patch was published on 2026-06-10: Version 0.47.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-54919 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-54919?

Check whether you run Yhirose Httplib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-54919: yhirose cpp-httplib certificate validation bypass for IP-literal hosts

CVE-2026-54919 · Severity: high · CVSS 7.4 · Published 2026-07-10

cpp-httplib is a widely used C++ library for adding web server and client functionality to applications. A security flaw in how the library handles encrypted (HTTPS) connections to specific IP addresses allows attackers to bypass security certificate checks. This could enable a "man-in-the-middle" attack where an unauthorized party intercepts, reads, or modifies sensitive data transmitted between the application and the server.

Vendors: Yhirose.

Quick answers

Is CVE-2026-54919 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-54919 being exploited in the wild.
How severe is CVE-2026-54919?: High severity, with a CVSS score of 7.4, published 10 July 2026.
Which products and versions are affected?: Yhirose Httplib 0.31.0 - 0.46.1.
Is there a fix for CVE-2026-54919?: A patch was published on 2026-06-10: Version 0.47.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-54919 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-54919?: Check whether you run Yhirose Httplib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A certificate validation bypass exists in cpp-httplib when using Mbed TLS (v0.31.0-0.46.1) or wolfSSL (v0.33.0-0.46.1) backends. When a client connects to an IP-literal host (e.g., https://1.1.1.1/) with certificate verification enabled, the library incorrectly downgrades or skips certificate chain validation. Specifically, SSLClient only performs a post-handshake IP SAN match without verifying the trust chain, and WebSocketClient on Mbed TLS may skip verification entirely. An attacker capable of intercepting network traffic can present a self-signed or untrusted certificate with a matching IP SAN to decrypt or alter communications. This issue is resolved in version 0.47.0 by ensuring chain verification remains active for IP hosts and performing identity checks post-handshake.

Affected products

yhirose cpp-httplib 0.31.0 - 0.46.1

Timeline

2026-06-10: patched: Version 0.47.0 released
2026-06-16: advisory: GitHub Security Advisory published
2026-07-10: disclosed: CVE-2026-54919 published to NVD

References

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