When a user invokes curl using a schemeless URL combined with
`--proto-default` sftp (or scp), a disconnect occurs between the tool layer
and libcurl. The tool layer incorrectly infers the URL scheme, which
erroneously bypasses the initialization of critical SSH security options like
CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the
libcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes
the connection via SFTP/SCP as specified. Because the tool layer skipped the
security configuration, these SSH host verification options are silently
omitted, causing curl to connect to an unverified SSH remote host without
throwing an error.
References
| Link | Resource |
|---|---|
| https://curl.se/docs/CVE-2026-12064.html | Patch Vendor Advisory |
| https://curl.se/docs/CVE-2026-12064.json | Vendor Advisory |
| https://hackerone.com/reports/3797526 | Exploit Issue Tracking Third Party Advisory |
| https://hackerone.com/reports/3797526 | Exploit Issue Tracking Third Party Advisory |
Configurations
History
07 Jul 2026, 19:43
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Haxx curl
Haxx |
|
| CPE | cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* | |
| CWE | CWE-295 | |
| References | () https://curl.se/docs/CVE-2026-12064.html - Patch, Vendor Advisory | |
| References | () https://curl.se/docs/CVE-2026-12064.json - Vendor Advisory | |
| References | () https://hackerone.com/reports/3797526 - Exploit, Issue Tracking, Third Party Advisory |
06 Jul 2026, 19:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.5 |
| References | () https://hackerone.com/reports/3797526 - |
03 Jul 2026, 07:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-03 07:16
Updated : 2026-07-07 19:43
NVD link : CVE-2026-12064
Mitre link : CVE-2026-12064
CVE.ORG link : CVE-2026-12064
JSON object : View
Products Affected
haxx
- curl
CWE
CWE-295
Improper Certificate Validation