{"id":"CVE-2026-5545","summary":"wrong reuse of HTTP Negotiate connection","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...","aliases":["CURL-CVE-2026-5545"],"modified":"2026-07-08T08:13:45.582478979Z","published":"2026-05-13T08:27:26.065Z","related":["SUSE-SU-2026:1717-1","SUSE-SU-2026:1940-1","SUSE-SU-2026:21452-1","SUSE-SU-2026:22146-1","SUSE-SU-2026:22156-1","SUSE-SU-2026:2703-1","openSUSE-SU-2026:10674-1","openSUSE-SU-2026:20973-1"],"database_specific":{"unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"8.19.0"},{"last_affected":"8.19.0"},{"introduced":"8.18.0"},{"last_affected":"8.18.0"},{"introduced":"8.17.0"},{"last_affected":"8.17.0"},{"introduced":"8.16.0"},{"last_affected":"8.16.0"},{"introduced":"8.15.0"},{"last_affected":"8.15.0"},{"introduced":"8.14.1"},{"last_affected":"8.14.1"},{"introduced":"8.14.0"},{"last_affected":"8.14.0"},{"introduced":"8.13.0"},{"last_affected":"8.13.0"},{"introduced":"8.12.1"},{"last_affected":"8.12.1"},{"introduced":"8.12.0"},{"last_affected":"8.12.0"},{"introduced":"8.11.1"},{"last_affected":"8.11.1"},{"introduced":"8.11.0"},{"last_affected":"8.11.0"},{"introduced":"8.10.1"},{"last_affected":"8.10.1"},{"introduced":"8.10.0"},{"last_affected":"8.10.0"},{"introduced":"8.9.1"},{"last_affected":"8.9.1"},{"introduced":"8.9.0"},{"last_affected":"8.9.0"},{"introduced":"8.8.0"},{"last_affected":"8.8.0"},{"introduced":"8.7.1"},{"last_affected":"8.7.1"},{"introduced":"8.7.0"},{"last_affected":"8.7.0"},{"introduced":"8.6.0"},{"last_affected":"8.6.0"},{"introduced":"8.5.0"},{"last_affected":"8.5.0"},{"introduced":"8.4.0"},{"last_affected":"8.4.0"},{"introduced":"8.3.0"},{"last_affected":"8.3.0"},{"introduced":"8.2.1"},{"last_affected":"8.2.1"},{"introduced":"8.2.0"},{"last_affected":"8.2.0"},{"introduced":"8.1.2"},{"last_affected":"8.1.2"},{"introduced":"8.1.1"},{"last_affected":"8.1.1"},{"introduced":"8.1.0"},{"last_affected":"8.1.0"},{"introduced":"8.0.1"},{"last_affected":"8.0.1"},{"introduced":"8.0.0"},{"last_affected":"8.0.0"},{"introduced":"7.88.1"},{"last_affected":"7.88.1"},{"introduced":"7.88.0"},{"last_affected":"7.88.0"},{"introduced":"7.87.0"},{"last_affected":"7.87.0"},{"introduced":"7.86.0"},{"last_affected":"7.86.0"},{"introduced":"7.85.0"},{"last_affected":"7.85.0"},{"introduced":"7.84.0"},{"last_affected":"7.84.0"},{"introduced":"7.83.1"},{"last_affected":"7.83.1"},{"introduced":"7.83.0"},{"last_affected":"7.83.0"},{"introduced":"7.82.0"},{"last_affected":"7.82.0"},{"introduced":"7.81.0"},{"last_affected":"7.81.0"},{"introduced":"7.80.0"},{"last_affected":"7.80.0"},{"introduced":"7.79.1"},{"last_affected":"7.79.1"},{"introduced":"7.79.0"},{"last_affected":"7.79.0"},{"introduced":"7.78.0"},{"last_affected":"7.78.0"},{"introduced":"7.77.0"},{"last_affected":"7.77.0"},{"introduced":"7.76.1"},{"last_affected":"7.76.1"},{"introduced":"7.76.0"},{"last_affected":"7.76.0"},{"introduced":"7.75.0"},{"last_affected":"7.75.0"},{"introduced":"7.74.0"},{"last_affected":"7.74.0"},{"introduced":"7.73.0"},{"last_affected":"7.73.0"},{"introduced":"7.72.0"},{"last_affected":"7.72.0"},{"introduced":"7.71.1"},{"last_affected":"7.71.1"},{"introduced":"7.71.0"},{"last_affected":"7.71.0"},{"introduced":"7.70.0"},{"last_affected":"7.70.0"},{"introduced":"7.69.1"},{"last_affected":"7.69.1"},{"introduced":"7.69.0"},{"last_affected":"7.69.0"},{"introduced":"7.68.0"},{"last_affected":"7.68.0"},{"introduced":"7.67.0"},{"last_affected":"7.67.0"},{"introduced":"7.66.0"},{"last_affected":"7.66.0"},{"introduced":"7.65.3"},{"last_affected":"7.65.3"},{"introduced":"7.65.2"},{"last_affected":"7.65.2"},{"introduced":"7.65.1"},{"last_affected":"7.65.1"},{"introduced":"7.65.0"},{"last_affected":"7.65.0"},{"introduced":"7.64.1"},{"last_affected":"7.64.1"},{"introduced":"7.64.0"},{"last_affected":"7.64.0"},{"introduced":"7.63.0"},{"last_affected":"7.63.0"},{"introduced":"7.62.0"},{"last_affected":"7.62.0"},{"introduced":"7.61.1"},{"last_affected":"7.61.1"},{"introduced":"7.61.0"},{"last_affected":"7.61.0"},{"introduced":"7.60.0"},{"last_affected":"7.60.0"},{"introduced":"7.59.0"},{"last_affected":"7.59.0"},{"introduced":"7.58.0"},{"last_affected":"7.58.0"},{"introduced":"7.57.0"},{"last_affected":"7.57.0"},{"introduced":"7.56.1"},{"last_affected":"7.56.1"},{"introduced":"7.56.0"},{"last_affected":"7.56.0"},{"introduced":"7.55.1"},{"last_affected":"7.55.1"},{"introduced":"7.55.0"},{"last_affected":"7.55.0"},{"introduced":"7.54.1"},{"last_affected":"7.54.1"},{"introduced":"7.54.0"},{"last_affected":"7.54.0"},{"introduced":"7.53.1"},{"last_affected":"7.53.1"},{"introduced":"7.53.0"},{"last_affected":"7.53.0"},{"introduced":"7.52.1"},{"last_affected":"7.52.1"},{"introduced":"7.52.0"},{"last_affected":"7.52.0"},{"introduced":"7.51.0"},{"last_affected":"7.51.0"},{"introduced":"7.50.3"},{"last_affected":"7.50.3"},{"introduced":"7.50.2"},{"last_affected":"7.50.2"},{"introduced":"7.50.1"},{"last_affected":"7.50.1"},{"introduced":"7.50.0"},{"last_affected":"7.50.0"},{"introduced":"7.49.1"},{"last_affected":"7.49.1"},{"introduced":"7.49.0"},{"last_affected":"7.49.0"},{"introduced":"7.48.0"},{"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