Bug 2535991 - CVE-2026-19931 curl: libcurl: Information disclosure via incorrect connection reuse with Negotiate authentication [fedora-all]
Summary: CVE-2026-19931 curl: libcurl: Information disclosure via incorrect connection...
Keywords:
Status: ON_QA
Alias: None
Product: Fedora
Classification: Fedora
Component: curl
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Jan Macku
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["c134493f-e35c-4e0f-a4dc-0...
Depends On:
Blocks: CVE-2026-19931
TreeView+ depends on / blocked
 
Reported: 2026-09-17 13:10 UTC by Srikanth Balasubramanian
Modified: 2026-10-10 01:58 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Srikanth Balasubramanian 2026-09-17 13:10:55 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-09-30 08:46:44 UTC
FEDORA-2026-663a2d0ba4 (curl-8.21.0-6.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-663a2d0ba4

Comment 2 Fedora Update System 2026-10-01 02:19:28 UTC
FEDORA-2026-663a2d0ba4 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-663a2d0ba4`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-663a2d0ba4

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 3 Fedora Update System 2026-10-05 00:17:08 UTC
FEDORA-2026-663a2d0ba4 (curl-8.21.0-6.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2026-10-09 07:44:53 UTC
FEDORA-2026-91d799048a (curl-8.18.0-13.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-91d799048a

Comment 5 Fedora Update System 2026-10-10 01:58:26 UTC
FEDORA-2026-91d799048a has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91d799048a`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91d799048a

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.


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