{"id":"CVE-2026-4873","title":"A vulnerability exists where a connection requiring TLS incorrectly reuses an\nexisting unencrypted connection from the same connection pool","summary":"A vulnerability exists where a connection requiring TLS incorrectly reuses an\nexisting unencrypted connection from the same connection pool. If an initial\ntransfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request\nto …","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-319","CWE-295"],"vendor":"haxx","product":"curl","affected":["curl >= 7.20.0, < 8.20.0"],"patched":["curl 8.20.0"],"published":"2026-05-13","updated":"2026-09-15","sourceUpdated":"2026-09-15T07:16:28.367","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-4873","references":[{"url":"https://curl.se/docs/CVE-2026-4873.html","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://curl.se/docs/CVE-2026-4873.json","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://hackerone.com/reports/3621851","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"http://www.openwall.com/lists/oss-security/2026/04/29/7","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-05-13T19:29:14.521822Z"},"epss":0.00329,"epssPercentile":0.26136,"ingestedAt":"2026-09-15T07:33:29.264Z","slug":"CVE-2026-4873","body":"## Overview\n\nA vulnerability exists where a connection requiring TLS incorrectly reuses an\nexisting unencrypted connection from the same connection pool. If an initial\ntransfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request\nto that same host bypasses the TLS requirement and instead transmit data\nunencrypted.\n\n## Affected\n\n- `curl >= 7.20.0, < 8.20.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `curl 8.20.0`","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}