{"id":"CVE-2026-19931","summary":"Negotiate ambient user conn reuse","details":"A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given\nhostname using Negotiate authentication, when the initial request is done\nusing empty credentials. This can make user B's request get sent over user A's\npreviously authenticated connection.","aliases":["CURL-CVE-2026-19931"],"modified":"2026-09-18T11:30:50.332572324Z","published":"2026-09-06T17:47:43.523Z","related":["openSUSE-SU-2026:11696-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19931.json","unresolved_ranges":[{"extracted_events":[{"introduced":"7.64.1"},{"fixed":"8.14.2"},{"introduced":"8.15.0"},{"fixed":"8.16.1"},{"introduced":"8.17.0"},{"fixed":"8.20.1"},{"introduced":"6c6035532383e300c712e4c1cd9fdd749ed5cf59"},{"fixed":"7103a93b05bc69ea98ed9d05d02fa9eeba533f2f"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"curl","cwe_ids":["CWE-488"]},"references":[{"type":"WEB","url":"https://curl.se/docs/CVE-2026-19931.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-19931.json"},{"type":"WEB","url":"https://hackerone.com/reports/3923520"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19931.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19931"},{"type":"PACKAGE","url":"https://github.com/curl/curl.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/curl/curl","events":[{"introduced":"521bbbe29928f9bc1c61306df612e856d45cbe5a"},{"fixed":"01346829096c61b372692f6dc43ffa778c6caccd"}],"database_specific":{"source":"CPE_RANGE","cpe":"cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"7.64.1"},{"fixed":"8.22.0"}]}}],"versions":["7.64.1","7.65.0","7.65.1","7.65.2","7.65.3","7.66.0","7.67.0","7.68.0","7.69.0","7.69.1","7.70.0","7.71.0","7.71.1","7.72.0","7.73.0","7.74.0","7.75.0","7.76.0","7.76.1","7.77.0","7.78.0","7.79.0","7.79.1","7.80.0","7.81.0","7.82.0","7.83.0","7.83.1","7.84.0","7.85.0","7.86.0","7.87.0","7.88.0","7.88.1","8.0.0","8.0.1","8.1.0","8.1.1","8.1.2","8.10.0","8.10.1","8.11.0","8.11.1","8.12.0","8.12.1","8.13.0","8.14.0","8.14.1","8.15.0","8.16.0","8.17.0","8.18.0","8.19.0","8.2.0","8.2.1","8.20.0","8.3.0","8.4.0","8.5.0","8.6.0","8.7.0","8.7.1","8.8.0","8.9.0","8.9.1","rc-8_22_0-3","rc-8_22_0-2","rc-8_22_0-1","curl-8_21_0","rc-8_21_0-3","rc-8_21_0-2","rc-8_21_0-1","curl-8_20_0","rc-8_20_0-3","rc-8_20_0-2","rc-8_20_0-1","curl-8_19_0","curl-8_18_0","curl-8_17_0","curl-8_16_0","curl-8_15_0","curl-8_14_1","curl-8_14_0","curl-8_13_0","curl-8_12_1","curl-8_12_0","curl-8_11_1","curl-8_11_0","curl-8_10_1","curl-8_10_0","curl-8_9_1","curl-8_9_0","curl-8_8_0","curl-8_7_1","curl-8_7_0","curl-8_6_0","curl-8_5_0","curl-8_4_0","curl-8_3_0","curl-8_2_1","curl-8_2_0","curl-8_1_2","curl-8_1_1","curl-8_1_0","curl-8_0_1","curl-8_0_0","curl-7_88_1","curl-7_88_0","curl-7_87_0","curl-7_86_0","curl-7_85_0","curl-7_84_0","curl-7_83_1","curl-7_83_0","curl-7_82_0","curl-7_81_0","curl-7_80_0","curl-7_79_1","curl-7_79_0","curl-7_78_0","curl-7_77_0","curl-7_76_1","curl-7_76_0","curl-7_75_0","curl-7_74_0","curl-7_73_0","curl-7_72_0","curl-7_71_1","curl-7_71_0","curl-7_70_0","curl-7_69_1","curl-7_69_0","curl-7_68_0","curl-7_67_0","curl-7_66_0","curl-7_65_3","curl-7_65_2","curl-7_65_1","curl-7_65_0","curl-7_64_1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-19931.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}