Bug 2497409

Summary:	CVE-2026-9547 mingw-curl: curl: Man-in-the-middle attack via SSH host key bypass [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Jon Moroney <jmoroney>
Component:	mingw-curl	Assignee:	Michael Cronenworth <mike>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	45	CC:	mike
Target Milestone:	---	Keywords:	Reopened, Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["ee76bccd-42cc-40c3-991b-b60c1f0bb23b"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-09-07 05:53:17 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2496758

Description Jon Moroney 2026-07-06 17:59:39 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.

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.

Comment 1 Aoife Moloney 2026-08-17 15:14:41 UTC

This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.