CVE-2026-12064
CVE-2026-12064 · proto-default skips SSH verification
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.5 · High · EPSS 0.4% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
curl
- Versions
- ≥ 7.81.0, < 8.14.2: Affected (semver)
- ≥ 8.15.0, < 8.16.1: Affected (semver)
- ≥ 8.17.0, < 8.20.1: Affected (semver)
Update to 8.14.2; Update to 8.16.1; Update to 8.20.1
curl
- Versions
- ≥ 18270893abdb19f0ca170c118f8a2847dbd304be, < ab3bb8cd8be8f9d4acb97da0418abc279182041e: Affected (git)
No fix published
curl
- Versions
- 8.20.0: Affected
- 8.19.0: Affected
- 8.18.0: Affected
- 8.17.0: Affected
- 8.16.0: Affected
- 8.15.0: Affected
- 8.14.1: Affected
- 8.14.0: Affected
- 8.13.0: Affected
- 8.12.1: Affected
- 8.12.0: Affected
- 8.11.1: Affected
- 8.11.0: Affected
- 8.10.1: Affected
- 8.10.0: Affected
- 8.9.1: Affected
- 8.9.0: Affected
- 8.8.0: Affected
- 8.7.1: Affected
- 8.7.0: Affected
- 8.6.0: Affected
- 8.5.0: Affected
- 8.4.0: Affected
- 8.3.0: Affected
- 8.2.1: Affected
- 8.2.0: Affected
- 8.1.2: Affected
- 8.1.1: Affected
- 8.1.0: Affected
- 8.0.1: Affected
- 8.0.0: Affected
- 7.88.1: Affected
- 7.88.0: Affected
- 7.87.0: Affected
- 7.86.0: Affected
- 7.85.0: Affected
- 7.84.0: Affected
- 7.83.1: Affected
- 7.83.0: Affected
- 7.82.0: Affected
- 7.81.0: Affected
No fix published
curl Debian:12
- Versions
- 7.88.1-10
- 7.88.1-10+deb12u1
- 7.88.1-10+deb12u11
- 7.88.1-10+deb12u12
- 7.88.1-10+deb12u13
- 7.88.1-10+deb12u14
- 7.88.1-10+deb12u15
- 7.88.1-10+deb12u1~bpo11+1
- 7.88.1-10+deb12u2
- 7.88.1-10+deb12u3
- 7.88.1-10+deb12u3~bpo11+1
- 7.88.1-10+deb12u4
- 7.88.1-10+deb12u5
- 7.88.1-10+deb12u5~bpo11+1
- 7.88.1-10+deb12u6
- 7.88.1-10+deb12u6~bpo11+1
- 7.88.1-10+deb12u7
- 7.88.1-10+deb12u8
- 7.88.1-10+deb12u9
- 7.88.1-11
- 8.0.1-1~exp1
- 8.10.0-1
- 8.10.0-2
- 8.10.1-1
- 8.10.1-1~bpo12+1
- 8.10.1-2
- 8.11.0-1
- 8.11.1-1
- 8.11.1-1~bpo12+1
- 8.12.0+git20250209.89ed161+ds-1
- 8.12.0+git20250209.89ed161+ds-1~bpo12+1
- 8.12.1-1
- 8.12.1-2
- 8.12.1-2~bpo12+1
- 8.12.1-3
- 8.12.1-3~bpo12+1
- 8.13.0-1
- 8.13.0-1+exp1
- 8.13.0-2
- 8.13.0-2+exp1
- 8.13.0-3
- 8.13.0-4
- 8.13.0-4+exp1
- 8.13.0-5
- 8.13.0-5+exp1
- 8.13.0-5~bpo12+1
- 8.13.0~rc-1~exp1
- 8.13.0~rc-1~exp2
- 8.13.0~rc2-1
- 8.13.0~rc2-2
- 8.13.0~rc3-1
- 8.13.0~rc3-1+exp1
- 8.14.0-1
- 8.14.0-1+exp1
- 8.14.0~rc1-1+exp1
- 8.14.0~rc2-1+exp1
- 8.14.0~rc3-1+exp1
- 8.14.1-1
- 8.14.1-1~bpo12+1
- 8.14.1-2
- 8.14.1-2+exp1
- 8.14.1-2~bpo12+1
- 8.15.0-1
- 8.15.0-1~bpo13+1
- 8.15.0-1~exp1
- 8.15.0~rc1-1exp1
- 8.15.0~rc2-1~exp1
- 8.15.0~rc3-1~exp1
- 8.16.0-1
- 8.16.0-1+exp1
- 8.16.0-1~bpo13+1
- 8.16.0-2
- 8.16.0-3
- 8.16.0-4
- 8.16.0-4~bpo13+1
- 8.16.0~rc1-1~exp1
- 8.16.0~rc2-1
- 8.16.0~rc2-2
- 8.16.0~rc3-1
- 8.17.0-1
- 8.17.0-2
- 8.17.0-3
- 8.17.0~rc1-1~exp1
- 8.17.0~rc2-1
- 8.17.0~rc3-1
- 8.18.0-1
- 8.18.0-1~bpo13+1
- 8.18.0-2
- 8.18.0~rc1-1+exp1
- 8.18.0~rc2-1
- 8.18.0~rc3-1
- 8.19.0-1
- 8.19.0-1+exp1
- 8.19.0-1~bpo13+1
- 8.19.0-2
- 8.19.0-3
- 8.19.0-3+exp1
- 8.19.0-3+exp2
- 8.19.0~rc1-1~exp1
- 8.19.0~rc2-1
- 8.19.0~rc2-2
- 8.19.0~rc3-1
- 8.2.1-1
- 8.2.1-2
- 8.2.1-2~bpo12+1
- 8.20.0-1
- 8.20.0-1+exp
- 8.20.0-2
- 8.20.0-2+exp1
- 8.20.0-2~bpo13+1
- 8.20.0-3
- 8.20.0-4
- 8.20.0-5
- 8.20.0-5~bpo13+1
- 8.20.0~rc1-1+exp1
- 8.20.0~rc1-1+exp2
- 8.20.0~rc1-1+exp3
- 8.20.0~rc2-1
- 8.20.0~rc2-1+exp1
- 8.20.0~rc3-1
- 8.20.0~rc3-1+exp1
- 8.21.0-1
- 8.21.0-1+exp1
- 8.21.0-2
- 8.21.0-2+exp1
- 8.21.0-2~bpo13+1
- 8.21.0~rc1-1+exp1
- 8.21.0~rc2-1
- 8.21.0~rc2-1+exp1
- 8.21.0~rc3-1
- 8.21.0~rc3-1+exp1
- 8.22.0-1
- 8.22.0-1+exp1
- 8.22.0~rc2-1
- 8.22.0~rc2-2
- 8.22.0~rc3-1
- 8.22.0~rc3-1+exp1
- 8.23.0~rc1-1
- 8.23.0~rc1-2
- 8.23.0~rc2-1
- 8.23.0~rc2-1+exp1
- 8.3.0-1
- 8.3.0-2
- 8.3.0-2~bpo12+1
- 8.3.0-2~exp1
- 8.3.0-3
- 8.4.0-1
- 8.4.0-2
- 8.4.0-2~bpo12+1
- 8.5.0-1
- 8.5.0-1+exp1
- 8.5.0-2
- 8.5.0-2+exp1
- 8.5.0-2~bpo12+1
- 8.6.0-1
- 8.6.0-1.1
- 8.6.0-2
- 8.6.0-3
- 8.6.0-3.1
- 8.6.0-3.1~exp1
- 8.6.0-3.1~exp2
- 8.6.0-3.2
- 8.6.0-4
- 8.7.1-1
- 8.7.1-1+exp1
- 8.7.1-2
- 8.7.1-3
- 8.7.1-4
- 8.7.1-5
- 8.7.1-5+exp1
- 8.7.1-5~bpo12+1
- 8.8.0-1
- 8.8.0-1+exp1
- 8.8.0-1+exp2
- 8.8.0-1~bpo12+1
- 8.8.0-2
- 8.8.0-3
- 8.8.0-4
- 8.9.0-1
- 8.9.0-2
- 8.9.0-3
- 8.9.1-1
- 8.9.1-2
- 8.9.1-2~bpo12+1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
curl Debian:13
- Versions
- 8.14.1-2
- 8.14.1-2+deb13u1
- 8.14.1-2+deb13u2
- 8.14.1-2+deb13u2~bpo13+1
- 8.14.1-2+deb13u3
- 8.14.1-2+deb13u4
- 8.14.1-2+deb13u5
- 8.14.1-2+exp1
- 8.15.0-1
- 8.15.0-1~bpo13+1
- 8.15.0-1~exp1
- 8.15.0~rc1-1exp1
- 8.15.0~rc2-1~exp1
- 8.15.0~rc3-1~exp1
- 8.16.0-1
- 8.16.0-1+exp1
- 8.16.0-1~bpo13+1
- 8.16.0-2
- 8.16.0-3
- 8.16.0-4
- 8.16.0-4~bpo13+1
- 8.16.0~rc1-1~exp1
- 8.16.0~rc2-1
- 8.16.0~rc2-2
- 8.16.0~rc3-1
- 8.17.0-1
- 8.17.0-2
- 8.17.0-3
- 8.17.0~rc1-1~exp1
- 8.17.0~rc2-1
- 8.17.0~rc3-1
- 8.18.0-1
- 8.18.0-1~bpo13+1
- 8.18.0-2
- 8.18.0~rc1-1+exp1
- 8.18.0~rc2-1
- 8.18.0~rc3-1
- 8.19.0-1
- 8.19.0-1+exp1
- 8.19.0-1~bpo13+1
- 8.19.0-2
- 8.19.0-3
- 8.19.0-3+exp1
- 8.19.0-3+exp2
- 8.19.0~rc1-1~exp1
- 8.19.0~rc2-1
- 8.19.0~rc2-2
- 8.19.0~rc3-1
- 8.20.0-1
- 8.20.0-1+exp
- 8.20.0-2
- 8.20.0-2+exp1
- 8.20.0-2~bpo13+1
- 8.20.0-3
- 8.20.0-4
- 8.20.0-5
- 8.20.0-5~bpo13+1
- 8.20.0~rc1-1+exp1
- 8.20.0~rc1-1+exp2
- 8.20.0~rc1-1+exp3
- 8.20.0~rc2-1
- 8.20.0~rc2-1+exp1
- 8.20.0~rc3-1
- 8.20.0~rc3-1+exp1
- 8.21.0-1
- 8.21.0-1+exp1
- 8.21.0-2
- 8.21.0-2+exp1
- 8.21.0-2~bpo13+1
- 8.21.0~rc1-1+exp1
- 8.21.0~rc2-1
- 8.21.0~rc2-1+exp1
- 8.21.0~rc3-1
- 8.21.0~rc3-1+exp1
- 8.22.0-1
- 8.22.0-1+exp1
- 8.22.0~rc2-1
- 8.22.0~rc2-2
- 8.22.0~rc3-1
- 8.22.0~rc3-1+exp1
- 8.23.0~rc1-1
- 8.23.0~rc1-2
- 8.23.0~rc2-1
- 8.23.0~rc2-1+exp1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
curl Debian:14
- Versions
- 8.14.1-2
- 8.14.1-2+exp1
- 8.15.0-1
- 8.15.0-1~bpo13+1
- 8.15.0-1~exp1
- 8.15.0~rc1-1exp1
- 8.15.0~rc2-1~exp1
- 8.15.0~rc3-1~exp1
- 8.16.0-1
- 8.16.0-1+exp1
- 8.16.0-1~bpo13+1
- 8.16.0-2
- 8.16.0-3
- 8.16.0-4
- 8.16.0-4~bpo13+1
- 8.16.0~rc1-1~exp1
- 8.16.0~rc2-1
- 8.16.0~rc2-2
- 8.16.0~rc3-1
- 8.17.0-1
- 8.17.0-2
- 8.17.0-3
- 8.17.0~rc1-1~exp1
- 8.17.0~rc2-1
- 8.17.0~rc3-1
- 8.18.0-1
- 8.18.0-1~bpo13+1
- 8.18.0-2
- 8.18.0~rc1-1+exp1
- 8.18.0~rc2-1
- 8.18.0~rc3-1
- 8.19.0-1
- 8.19.0-1+exp1
- 8.19.0-1~bpo13+1
- 8.19.0-2
- 8.19.0-3
- 8.19.0-3+exp1
- 8.19.0-3+exp2
- 8.19.0~rc1-1~exp1
- 8.19.0~rc2-1
- 8.19.0~rc2-2
- 8.19.0~rc3-1
- 8.20.0-1
- 8.20.0-1+exp
- 8.20.0-2
- 8.20.0-2+exp1
- 8.20.0-2~bpo13+1
- 8.20.0-3
- 8.20.0-4
- 8.20.0-5
- 8.20.0-5~bpo13+1
- 8.20.0~rc1-1+exp1
- 8.20.0~rc1-1+exp2
- 8.20.0~rc1-1+exp3
- 8.20.0~rc2-1
- 8.20.0~rc2-1+exp1
- 8.20.0~rc3-1
- 8.20.0~rc3-1+exp1
- 8.21.0~rc1-1+exp1
- 8.21.0~rc2-1
- 8.21.0~rc2-1+exp1
- Affected ranges
- ECOSYSTEM: < 8.21.0~rc3-1
Update to 8.21.0~rc3-1
curl Ubuntu:25.10
- Versions
- 8.12.1-3ubuntu1
- 8.13.0-5ubuntu1
- 8.14.1-1ubuntu2
- 8.14.1-1ubuntu3
- 8.14.1-2ubuntu1
- 8.14.1-2ubuntu1.1
- 8.14.1-2ubuntu1.2
- 8.14.1-2ubuntu1.3
- 8.14.1-2ubuntu1.4
- Affected ranges
- ECOSYSTEM: < 8.14.1-2ubuntu1.5
Update to 8.14.1-2ubuntu1.5
curl Ubuntu:26.04:LTS
- Versions
- 8.14.1-2ubuntu1
- 8.17.0-1ubuntu1
- 8.18.0-1ubuntu1
- 8.18.0-1ubuntu2
- 8.18.0-1ubuntu2.1
- 8.18.0-1ubuntu2.2
- Affected ranges
- ECOSYSTEM: < 8.18.0-1ubuntu2.3
Update to 8.18.0-1ubuntu2.3