VULNERABILITY INTELLIGENCE

CVE-2026-12064

CVSS score7.5 HIGH

EPSS probability0.41%

CISA KEVNot currently listed

Published2026-07-03

Last modified2026-09-15

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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.

Weakness classification

CWE-295: Improper Certificate Validation
CWE-297: Improper Validation of Certificate with Host Mismatch

Primary references

2499f714-1537-4658-8207-48ae4bb9eae9 — Patch, Vendor Advisory
2499f714-1537-4658-8207-48ae4bb9eae9 — Vendor Advisory
2499f714-1537-4658-8207-48ae4bb9eae9 — Exploit, Issue Tracking, Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Issue Tracking, Third Party Advisory