proto-default skips SSH verification (curl curl)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.41 % · percentile 36 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- curl
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-297 — Improper Validation of Certificate with Host Mismatch
- CWE-295 — Improper Certificate Validation
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | CISA-ADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-41502
- GCVE · GCVE-0-2026-12064
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1351 — Multiples vulnérabilités dans Oracle MySQL · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1307 — Multiples vulnérabilités dans Curl · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1023 — Multiples vulnérabilités dans Tenable Security Center · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0873 — Multiples vulnérabilités dans Microsoft Azure Linux · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0797 — Multiples vulnérabilités dans cURL et libcurl · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*≥ 7.81.0 < 8.21.0
Affected products
| Product | Versions |
|---|---|
| curl · curl | affected 7.81.0 < 8.14.2 ; affected 8.15.0 < 8.16.1 ; affected 8.17.0 < 8.20.1 |
| curl · curl | affected 18270893abdb19f0ca170c118f8a2847dbd304be < ab3bb8cd8be8f9d4acb97da0418abc279182041e |
| curl · curl | affected 8.20.0 ; affected 8.19.0 ; affected 8.18.0 ; affected 8.17.0 ; affected 8.16.0 ; affected 8.15.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |