CVE-2026-12064

Friday, July 03, 2026

N/A

Summary

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.

Affected Software

Vendor	Product	Version Range	Status
curl	curl	`8.20.0 <= 8.20.0`	affected
curl	curl	`8.19.0 <= 8.19.0`	affected
curl	curl	`8.18.0 <= 8.18.0`	affected
curl	curl	`8.17.0 <= 8.17.0`	affected
curl	curl	`8.16.0 <= 8.16.0`	affected
curl	curl	`8.15.0 <= 8.15.0`	affected
curl	curl	`8.14.1 <= 8.14.1`	affected
curl	curl	`8.14.0 <= 8.14.0`	affected
curl	curl	`8.13.0 <= 8.13.0`	affected
curl	curl	`8.12.1 <= 8.12.1`	affected
curl	curl	`8.12.0 <= 8.12.0`	affected
curl	curl	`8.11.1 <= 8.11.1`	affected
curl	curl	`8.11.0 <= 8.11.0`	affected
curl	curl	`8.10.1 <= 8.10.1`	affected
curl	curl	`8.10.0 <= 8.10.0`	affected
curl	curl	`8.9.1 <= 8.9.1`	affected
curl	curl	`8.9.0 <= 8.9.0`	affected
curl	curl	`8.8.0 <= 8.8.0`	affected
curl	curl	`8.7.1 <= 8.7.1`	affected
curl	curl	`8.7.0 <= 8.7.0`	affected
curl	curl	`8.6.0 <= 8.6.0`	affected
curl	curl	`8.5.0 <= 8.5.0`	affected
curl	curl	`8.4.0 <= 8.4.0`	affected
curl	curl	`8.3.0 <= 8.3.0`	affected
curl	curl	`8.2.1 <= 8.2.1`	affected
curl	curl	`8.2.0 <= 8.2.0`	affected
curl	curl	`8.1.2 <= 8.1.2`	affected
curl	curl	`8.1.1 <= 8.1.1`	affected
curl	curl	`8.1.0 <= 8.1.0`	affected
curl	curl	`8.0.1 <= 8.0.1`	affected
curl	curl	`8.0.0 <= 8.0.0`	affected
curl	curl	`7.88.1 <= 7.88.1`	affected
curl	curl	`7.88.0 <= 7.88.0`	affected
curl	curl	`7.87.0 <= 7.87.0`	affected
curl	curl	`7.86.0 <= 7.86.0`	affected
curl	curl	`7.85.0 <= 7.85.0`	affected
curl	curl	`7.84.0 <= 7.84.0`	affected
curl	curl	`7.83.1 <= 7.83.1`	affected
curl	curl	`7.83.0 <= 7.83.0`	affected
curl	curl	`7.82.0 <= 7.82.0`	affected
curl	curl	`7.81.0 <= 7.81.0`	affected

Weaknesses

CWE-297 Improper Validation of Certificate with Host Mismatch

References

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