proto-default skips SSH verification
Summary
| CVE | CVE-2026-12064 |
|---|---|
| State | PUBLISHED |
| Assigner | curl |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-03 07:16:24 UTC |
| Updated | 2026-07-03 07:16:24 UTC |
| Description | 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. |
Risk And Classification
Problem Types: CWE-297 Improper Validation of Certificate with Host Mismatch
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Curl | Curl | affected 8.20.0 8.20.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.19.0 8.19.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.18.0 8.18.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.17.0 8.17.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.16.0 8.16.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.15.0 8.15.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.14.1 8.14.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.14.0 8.14.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.13.0 8.13.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.12.1 8.12.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.12.0 8.12.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.11.1 8.11.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.11.0 8.11.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.10.1 8.10.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.10.0 8.10.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.9.1 8.9.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.9.0 8.9.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.8.0 8.8.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.7.1 8.7.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.7.0 8.7.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.6.0 8.6.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.5.0 8.5.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.4.0 8.4.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.3.0 8.3.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.2.1 8.2.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.2.0 8.2.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.1.2 8.1.2 semver | Not specified |
| CNA | Curl | Curl | affected 8.1.1 8.1.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.1.0 8.1.0 semver | Not specified |
| CNA | Curl | Curl | affected 8.0.1 8.0.1 semver | Not specified |
| CNA | Curl | Curl | affected 8.0.0 8.0.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.88.1 7.88.1 semver | Not specified |
| CNA | Curl | Curl | affected 7.88.0 7.88.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.87.0 7.87.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.86.0 7.86.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.85.0 7.85.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.84.0 7.84.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.83.1 7.83.1 semver | Not specified |
| CNA | Curl | Curl | affected 7.83.0 7.83.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.82.0 7.82.0 semver | Not specified |
| CNA | Curl | Curl | affected 7.81.0 7.81.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| hackerone.com/reports/3797526 | 2499f714-1537-4658-8207-48ae4bb9eae9 | hackerone.com | |
| curl.se/docs/CVE-2026-12064.html | 2499f714-1537-4658-8207-48ae4bb9eae9 | curl.se | |
| curl.se/docs/CVE-2026-12064.json | 2499f714-1537-4658-8207-48ae4bb9eae9 | curl.se | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: alienowo on hackerone (AntAISecurityLab) (en)
CNA: Daniel Stenberg (en)
There are currently no legacy QID mappings associated with this CVE.