CVE-2026-19931
High
High exploit probability or critical severity with a known exploit.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
1.2%
65.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-488
Published 2026-09-06 · modified 2026-09-15
Description
A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.