CVE-2026-19931

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://curl.se/docs/CVE-2026-19931.html	Patch Vendor Advisory
https://curl.se/docs/CVE-2026-19931.json	Vendor Advisory
https://hackerone.com/reports/3923520	Exploit Mitigation Third Party Advisory
https://hackerone.com/reports/3923520	Exploit Mitigation Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-09-06 18:17

Updated : 2026-09-15 07:16

NVD link : CVE-2026-19931

Mitre link : CVE-2026-19931

CVE.ORG link : CVE-2026-19931

JSON object : View

Products Affected

haxx

curl

CWE

CWE-488

Exposure of Data Element to Wrong Session

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