{"id":"UBUNTU-CVE-2026-9546","details":"A vulnerability in libcurl caused the HTTP `Referer:` header to persist even when explicitly cleared. While the documentation states that passing NULL to `CURLOPT_REFERER` suppresses the header, the option failed to clear the internal state. As a result, the previous referrer string was erroneously reused and sent in subsequent requests, potentially leaking sensitive information to unintended servers.","modified":"2026-06-30T03:45:07.198720622Z","published":"2026-06-24T14:00:00Z","withdrawn":"2026-06-30T01:55:01Z","upstream":["CVE-2026-9546"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-9546"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-9546"},{"type":"REPORT","url":"https://curl.se/L7HzKXisfJ/CVE-2026-9546.md"}],"affected":[{"package":{"name":"curl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/curl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.14.1-2ubuntu1","8.17.0-1ubuntu1","8.18.0-1ubuntu1","8.18.0-1ubuntu2","8.18.0-1ubuntu2.1"],"ecosystem_specific":{"binaries":[{"binary_name":"curl","binary_version":"8.18.0-1ubuntu2.1"},{"binary_name":"libcurl3t64-gnutls","binary_version":"8.18.0-1ubuntu2.1"},{"binary_name":"libcurl4t64","binary_version":"8.18.0-1ubuntu2.1"}],"priority_reason":"Upstream defined this as low severity"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9546.json"}}],"schema_version":"1.7.5","severity":[{"type":"Ubuntu","score":"low"}]}