{"id":"CVE-2026-12064","title":"When a user invokes curl using a schemeless URL combined with\n`--proto-default` sftp (or scp), a disconnect occurs between the tool layer\nand libcurl","summary":"When a user invokes curl using a schemeless URL combined with\n`--proto-default` sftp (or scp), a disconnect occurs between the tool layer\nand libcurl. The tool layer incorrectly infers the URL scheme, which\nerroneously bypasses the initi…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","cwe":["CWE-297","CWE-295","CWE-358"],"vendor":"haxx","product":"curl","affected":["curl >= 7.81.0, < 8.21.0"],"patched":["curl 8.21.0"],"published":"2026-07-03","updated":"2026-09-15","sourceUpdated":"2026-09-15T07:16:26.150","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-12064","references":[{"url":"https://curl.se/docs/CVE-2026-12064.html","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://curl.se/docs/CVE-2026-12064.json","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://hackerone.com/reports/3797526","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://hackerone.com/reports/3797526","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12064.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-12064"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2496768"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-12064"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12064"},{"url":"https://access.redhat.com/errata/RHSA-2026:55450"},{"url":"https://access.redhat.com/errata/RHSA-2026:29017"},{"url":"https://access.redhat.com/errata/RHSA-2026:34975"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-07-06T18:19:34.951461Z"},"epss":0.00399,"epssPercentile":0.33917,"ingestedAt":"2026-07-04T04:55:39.427Z","slug":"CVE-2026-12064","body":"## Overview\n\nWhen a user invokes curl using a schemeless URL combined with\n`--proto-default` sftp (or scp), a disconnect occurs between the tool layer\nand libcurl. The tool layer incorrectly infers the URL scheme, which\nerroneously bypasses the initialization of critical SSH security options like\nCURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the\nlibcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes\nthe connection via SFTP/SCP as specified. Because the tool layer skipped the\nsecurity configuration, these SSH host verification options are silently\nomitted, causing curl to connect to an unverified SSH remote host without\nthrowing an error.\n\n## Affected\n\n- `curl >= 7.81.0, < 8.21.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `curl 8.21.0`\n\n## Vendor advisories\n\n- **RHSA-2026:55450** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-08-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:55450)\n- **RHSA-2026:29017** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:29017)\n- **RHSA-2026:34975** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:34975)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":203487,"id":"CVE-2026-12064","ts":1789457645727,"field":"exploit_available","old":"false","new":"true"},{"seq":203486,"id":"CVE-2026-12064","ts":1789457645727,"field":"cvss","old":null,"new":"7.5"},{"seq":203485,"id":"CVE-2026-12064","ts":1789457645727,"field":"severity","old":"none","new":"high"}]}