CVE-2026-12064

Aliases:DEBIAN-CVE-2026-12064ALPINE-CVE-2026-12064CGA-2mq2-c47m-9j9rCGA-2r88-ffw5-7x6gCGA-4frh-666w-p7xfCGA-6534-26vm-cgv9CGA-9gq7-7g5v-793xCGA-cpmh-9gg5-f8cwCGA-fmfx-625m-j3mxCGA-gc55-4xf3-779hCGA-h5gc-4cpr-87wjCGA-hp5x-q7mw-wcrwCGA-hwwr-xxcx-g54rCGA-mpch-27q7-5g24CGA-p3jc-gvxp-796cCGA-qhvh-mgv7-gghjCGA-qwgc-hj88-83hfCGA-qwgf-mp9m-9h3rCGA-r9gw-xq5m-v3mcCGA-rvwp-mq67-g9h7CGA-vf49-32fq-3p7wCGA-xw26-9wx7-q3rvCGA-75f7-3p6w-jf84
Advisory lineage Upstream: 0 Downstream: 16
Modified
Published: 03 Jul 2026, 06:13
Last modified:15 Sept 2026, 06:02

Vulnerability Summary

Overall Risk (default)
medium
40/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.4% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

03 Jul 2026, 06:13
Published
Vulnerability first disclosed
15 Sept 2026, 06:02
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Trends

Current EPSS score: 0.40%• Percentile: 34%

Techniques & Countermeasures

  • CWE-297•Improper Validation of Certificate with Host Mismatch

    The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.

  • CWE-295•Improper Certificate Validation

    The product does not validate, or incorrectly validates, a certificate.

Affected Systems

  • alpine•curl

    ≥ 7.81.0, < 8.22.0-r0 | ≥ 7.81.0, < 8.21.0-r0

  • chainguard•eco-python-curl

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-bin

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-dev

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-doc

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-static

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-bin

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-dev

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-static

    < 8.21.0-r0

  • chainguard•libcurl4

    all

  • wolfi•libcurl4

    all

  • curl•curl

    8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0 | 8.7.1 | 8.7.0 | 8.6.0 | 8.5.0 | 8.4.0 | 8.3.0 | 8.2.1 | 8.2.0 | 8.1.2 | 8.1.1 | 8.1.0 | 8.0.1 | 8.0.0 | 7.88.1 | 7.88.0 | 7.87.0 | 7.86.0 | 7.85.0 | 7.84.0 | 7.83.1 | 7.83.0 | 7.82.0 | 7.81.0 | ≥ 7.81.0, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.20.1 | ≥ 18270893abdb19f0ca170c118f8a2847dbd304be, < ab3bb8cd8be8f9d4acb97da0418abc279182041e | 8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0 | 8.7.1 | 8.7.0 | 8.6.0 | 8.5.0 | 8.4.0 | 8.3.0 | 8.2.1 | 8.2.0 | 8.1.2 | 8.1.1 | 8.1.0 | 8.0.1 | 8.0.0 | 7.88.1 | 7.88.0 | 7.87.0 | 7.86.0 | 7.85.0 | 7.84.0 | 7.83.1 | 7.83.0 | 7.82.0 | 7.81.0

  • debian•curl

    all | all | < 8.21.0~rc3-1

  • haxx•curl

    ≥ 7.81.0, < 8.21.0

References (7)