Low 3.7Published Oct 14, 2026

CVE-2026-103930cpp-httplib open_stream serializes CRLF in request target into HTTP request line

Updated under an hour ago (2026-10-19 08:30 UTC)

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Every CVE for yhirose cpp-httplib

Exploited in the last 30 days

cpp-httplib is a C++ header-only HTTP/HTTPS library. From 0.29.0 until 0.51.0, Client::open_stream in httplib.h accepts a caller-controlled path that reaches detail::write_request_line() without the detail::encode_path() protection used by the ordinary buffered request path. Raw carriage-return and line-feed bytes in the path can therefore split the outbound HTTP/1.1 request line and inject attacker-shaped request metadata. Exploitation requires an embedding application to pass remote user input into the open_stream path and a backend or intermediary that interprets the injected bytes; the established impact is modification of backend-visible request data, not direct confidentiality or availability impact. This issue is fixed in version 0.51.0.

CVSS: 3.7 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-113
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

yhirose cpp-httplib yhirose:cpp_httplib (from the name)	from 0.29.0, < 0.51.0	CNA record

References

https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-vq69-f637-8fhrx-refsource-confirm
https://github.com/yhirose/cpp-httplib/pull/2501x-refsource-misc
https://github.com/yhirose/cpp-httplib/commit/255c075b82cf9f221e6e607e8e6789e6e2bf4c2ax-refsource-misc
https://github.com/yhirose/cpp-httplib/releases/tag/v0.51.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.