CVE-2026-92389

high

Description

libcurl's TFTP state machine fails to validate state transitions against the requested transfer direction, accepting opening server responses for both reads and writes interchangeably. A malicious TFTP server can respond to a download request in a way that forces the client into transmit mode, prompting libcurl to consume and transmit data from the handle's persistent `CURLOPT_READDATA` pointer - including data remaining from unrelated prior operations, such as an HTTP POST request executed on a reused handle.

References

https://hackerone.com/reports/4022568

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-105319

https://curl.se/docs/CVE-2026-92389.json

https://curl.se/docs/CVE-2026-92389.html

Details

Source: Mitre, NVD

Published: 2026-10-20

Updated: 2026-10-30

Risk Information

CVSS v2

Base Score: 7.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.1

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00721