{"id":"JLSEC-2026-1204","summary":"libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated...","details":"libcurl might in some circumstances reuse the wrong connection when asked to\ndo an authenticated HTTP(S) request after a Negotiate-authenticated one, when\nboth use the same host.\n\nlibcurl features a pool of recent connections so that subsequent requests can\nreuse an existing connection to avoid overhead.\n\nWhen reusing a connection a range of criteria must be met. Due to a logical\nerror in the code, a request that was issued by an application could\nwrongfully reuse an existing connection to the same server that was\nauthenticated using different credentials.\n\nAn application that first uses Negotiate authentication to a server with\n`user1:password1` and then does another operation to the same server asking\nfor any authentication method but for `user2:password2` (while the previous\nconnection is still alive) - the second request gets confused and wrongly\nreuses the same connection and sends the new request over that connection\nthinking it uses a mix of user1's and user2's credentials when it is in fact\nstill using the connection authenticated for user1...","modified":"2026-08-07T20:29:08.547846694Z","published":"2026-08-07T20:11:58.984Z","upstream":["CVE-2026-5545","EUVD-2026-29923","GHSA-6g7g-56fm-f8mp"],"database_specific":{"license":"CC-BY-4.0","sources":[{"modified":"2026-06-17T10:59:12.847Z","published":"2026-05-13T13:01:56.190Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-5545","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5545","database_specific":{"status":"Analyzed"},"id":"CVE-2026-5545","imported":"2026-08-07T19:54:38.595Z"},{"modified":"2026-05-13T21:33:08Z","published":"2026-05-13T18:30:52Z","url":"https://api.github.com/advisories/GHSA-6g7g-56fm-f8mp","html_url":"https://github.com/advisories/GHSA-6g7g-56fm-f8mp","id":"GHSA-6g7g-56fm-f8mp","imported":"2026-08-07T19:56:07.487Z"},{"id":"EUVD-2026-29923","imported":"2026-08-07T19:55:20.580Z","modified":"2026-05-13T17:46:40Z","published":"2026-05-13T08:27:26Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-29923","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-29923"}]},"references":[{"type":"WEB","url":"https://curl.se/docs/CVE-2026-5545.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-5545.json"},{"type":"WEB","url":"https://github.com/advisories/GHSA-6g7g-56fm-f8mp"},{"type":"WEB","url":"https://hackerone.com/reports/3642555"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5545"}],"affected":[{"package":{"name":"CURL_jll","ecosystem":"Julia","purl":"pkg:julia/CURL_jll?uuid=b21e61f3-bafc-59ac-ab14-4c5c62d6588d"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.20.0+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1204.json"}},{"package":{"name":"LibCURL_jll","ecosystem":"Julia","purl":"pkg:julia/LibCURL_jll?uuid=deac9b47-8bc7-5906-a0fe-35ac56dc84c0"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.20.0+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1204.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N"}]}