{"cve":"CVE-2026-19931","nvd":{"published":"2026-09-06T18:17:20.733","modified":"2026-09-15T07:16:27.290","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-488"],"references":["https://curl.se/docs/CVE-2026-19931.html","https://curl.se/docs/CVE-2026-19931.json","https://hackerone.com/reports/3923520","https://hackerone.com/reports/3923520"],"products":["haxx:curl"],"source":"nvd","synced_at":"2026-10-19T22:52:03.409947763+00:00"},"epss":{"cve":"CVE-2026-19931","score":0.01128,"percentile":0.66369,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}