Description


When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.

Related CPE's


Vulnerable

References




https://hackerone.com/reports/3751712

ExploitIssue TrackingThird Party Advisory

https://hackerone.com/reports/3751712

ExploitIssue TrackingThird Party Advisory

Weaknesses


2499f714-1537-4658-8207-48ae4bb9eae9

Secondary

CWE-297


NVD-CWE-Other

CVSS impact metrics


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

7.4 · High

Information


Source identifier

2499f714-1537-4658-8207-48ae4bb9eae9

Vulnerability status

Modified

Published

2026-07-03T07:16:25.990Z

3 months ago

Last modified

2026-09-15T07:16:35.310Z

3 weeks ago