When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.
CVSS Details
- CVSS 3.1 Base Score: 7.4
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade curl | Jul 6, 2026 | Jul 3, 2026 |
| Ibm Aix | — | Apply the fix or workaround for curl_advisory11 | Jul 28, 2026 | Jul 28, 2026 |
| Redhat Openshift | — | Upgrade rhcos | Sep 3, 2026 | Jul 3, 2026 |
| Redhat_linux | — | Upgrade libcurl-minimal-debuginfoUpgrade libcurl-minimalUpgrade curl-minimalUpgrade libcurlUpgrade curl-debugsourceUpgrade libcurl-debuginfoUpgrade curl-debuginfoUpgrade curl-minimal-debuginfoUpgrade libcurl-develUpgrade curl | Jul 17, 2026 | Jul 3, 2026 |
| Rocky_linux | — | Upgrade libcurlUpgrade libcurl-develUpgrade libcurl-debuginfoUpgrade curl-minimalUpgrade curlUpgrade curl-debugsourceUpgrade curl-debuginfoUpgrade libcurl-minimalUpgrade curl-minimal-debuginfoUpgrade libcurl-minimal-debuginfo | Aug 20, 2026 | Aug 17, 2026 |
| Ubuntu | — | Upgrade curlUpgrade curl (Ubuntu Pro)Upgrade libcurl3 (Ubuntu Pro)Upgrade libcurl3-nss (Ubuntu Pro)Upgrade libcurl3t64-gnutlsUpgrade libcurl3-gnutlsUpgrade libcurl4-gnutls-dev (Ubuntu Pro)Upgrade libcurl4Upgrade libcurl4-nss-dev (Ubuntu Pro)Upgrade libcurl4 (Ubuntu Pro)Upgrade libcurl3-gnutls (Ubuntu Pro)Upgrade libcurl4t64Upgrade libcurl4-openssl-devUpgrade libcurl4-nss-devUpgrade libcurl3-nssUpgrade libcurl4-openssl-dev (Ubuntu Pro)Upgrade libcurl4-gnutls-dev | Jul 1, 2026 | Jun 30, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 10, 2026 | Jul 3, 2026 |
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