Quick answers
- Is CVE-2026-46527 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-46527 being exploited in the wild.
- How severe is CVE-2026-46527?
- Informational severity, with a CVSS score of 8.7, published 29 May 2026.
- Which products and versions are affected?
- Yhirose Cpp-Httplib < 0.44.0.
- Is there a fix for CVE-2026-46527?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-46527 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-46527?
- Check whether you run Yhirose Cpp-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 logic flaw exists in the `get_client_ip()` function of `httplib.h`. When `Server::set_trusted_proxies()` is configured with a non-empty list, the server attempts to parse the `X-Forwarded-For` header. If an attacker sends a request with an empty, whitespace-only, or comma-only `X-Forwarded-For` header, the `detail::split` function fails to populate the `ip_list` vector. The code subsequently calls `ip_list.front()` on the empty vector, which is undefined behavior in C++. In most environments, this results in a segmentation fault or abnormal process termination. The vulnerability is reachable without authentication over the network. It is fixed in version 0.44.0.
Affected products
- yhirose cpp-httplib < 0.44.0
Timeline
- 2026-05-16: advisory: GitHub Security Advisory published
- 2026-05-29: disclosed: CVE published to NVD