---
id: "CVE-2026-86410"
kind: "vulnerability"
aliases: ["CVE-2026-86410"]
title: "curl: SSH host verification skipped when following redirects to SFTP or SCP"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["curl", "package", "scp", "scripts", "self-hosted", "sftp"]
not_affected_if: ["no-redirect-following", "no-sftp-or-scp"]
published_at: "2026-10-20T20:17:25+00:00"
first_seen_at: "2026-10-23T21:57:21+00:00"
updated_at: "2026-10-25T05:04:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86410", "first_seen_at": "2026-10-23T21:57:21+00:00"}]
---

# curl: SSH host verification skipped when following redirects to SFTP or SCP

The curl command line tool only applies SSH host verification options when a user directly requests an SFTP or SCP URL, not when the transfer is reached by following a redirect. An attacker who can redirect curl to an SSH server may get connections that skip the intended host key checks.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `curl --version` and compare the curl version against the fixed release in the sources, which the sources do not state: unknown
- Check whether scripts use `-L` or `--location` together with SFTP or SCP URLs, or with SSH host key options such as `--hostpubsha256`, `--hostpubmd5` or `--known-hosts`

## Fix

- Upgrade curl to a release that includes the fix; the fixed version is unknown from the sources
- Until patched, avoid following redirects (omit `-L`) when fetching sftp:// or scp:// URLs

## Timeline

- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-86410

## From the sources

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.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_