This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-86410 →

UBUNTU-CVE-2026-86410

A flaw in the curl command line tool's logic makes it only set SSH host verification options when interacting directly using SFTP or SCP, and not as a...

Original description

The description as published by the source.

A flaw in the curl command line tool's logic makes it only set SSH host verification options when interacting directly using SFTP or SCP, and not as a result of following a redirect. This means --knownhosts, --hostpubsha256, and --hostpubmd5 are never installed when the initial URL is HTTPS. If --location and --proto-redir +sftp is used and the server returns a Location: sftp://example.com redirect, the SFTP connection proceeds without any of the user's requested SSH host verification methods.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Affected packages

Ubuntu:26.10 curl

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:26.04:LTS curl

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.18.0-1ubuntu2.8"}]}]

References

advisory ubuntu.com
report ubuntu.com
report cve.org
report curl.se