{"id":"JLSEC-2026-1220","summary":"In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when...","details":"In this scenario, libcurl first uses a proper HTTP/3 server for the initial\ntransfers, and when it makes a second transfer to the same site it has been\nreplaced by the attacker's impostor machine - without a valid certificate.\n\nWhen libcurl returns to the hostname the second time with a cached SSL session\n(`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the\n`CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might\nsend off the second request's bytes on that new connection *before* enforcing\nthe certificate verification failure. Potentially leaking sensitive\ninformation.","modified":"2026-08-07T20:29:05.800395724Z","published":"2026-08-07T20:11:58.984Z","upstream":["CVE-2026-9545","EUVD-2026-41493","GHSA-6v72-wfcj-jv53"],"database_specific":{"sources":[{"database_specific":{"status":"Analyzed"},"id":"CVE-2026-9545","imported":"2026-08-07T19:54:38.989Z","modified":"2026-07-07T15:03:56.920Z","published":"2026-07-03T07:16:25.807Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-9545","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9545"},{"id":"GHSA-6v72-wfcj-jv53","imported":"2026-08-07T19:56:04.342Z","modified":"2026-07-06T18:30:50Z","published":"2026-07-03T09:31:27Z","url":"https://api.github.com/advisories/GHSA-6v72-wfcj-jv53","html_url":"https://github.com/advisories/GHSA-6v72-wfcj-jv53"},{"published":"2026-07-03T06:17:55Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-41493","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-41493","id":"EUVD-2026-41493","imported":"2026-08-07T19:55:05.504Z","modified":"2026-07-06T16:53:23Z"}],"license":"CC-BY-4.0"},"references":[{"type":"WEB","url":"https://curl.se/docs/CVE-2026-9545.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-9545.json"},{"type":"WEB","url":"https://github.com/advisories/GHSA-6v72-wfcj-jv53"},{"type":"WEB","url":"https://hackerone.com/reports/3752888"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9545"}],"affected":[{"package":{"name":"CURL_jll","ecosystem":"Julia","purl":"pkg:julia/CURL_jll?uuid=b21e61f3-bafc-59ac-ab14-4c5c62d6588d"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.11.0+0"},{"fixed":"8.21.0+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1220.json"}},{"package":{"name":"LibCURL_jll","ecosystem":"Julia","purl":"pkg:julia/LibCURL_jll?uuid=deac9b47-8bc7-5906-a0fe-35ac56dc84c0"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.11.0+0"},{"fixed":"8.21.0+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1220.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}