cpp-httplib open_stream serializes CRLF in request target into HTTP request line
Summary
| CVE | CVE-2026-103930 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-14 19:17:07 UTC |
| Updated | 2026-10-16 20:04:29 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 3.7 LOW from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS: 0.003660000 probability, percentile 0.288610000 (date 2026-10-16)
Problem Types: CWE-113 | CWE-113 CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 3.7 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
| 3.1 | CNA | DECLARED | 3.7 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Yhirose | Cpp-httplib | affected >= 0.29.0, < 0.51.0 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/yhirose/cpp-httplib/commit/255c075b82cf9f221e6e607e8e6789e6e2... | [email protected] | github.com | |
| github.com/yhirose/cpp-httplib/pull/2501 | [email protected] | github.com | |
| github.com/yhirose/cpp-httplib/releases/tag/v0.51.0 | [email protected] | github.com | |
| github.com/yhirose/cpp-httplib/security/advisories/GHSA-vq69-f637-8fhr | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.