Vulnerability · Published Oct 20, 2026 · Assigned by curl

CVE-2026-86410redirect to SFTP or SCP bypasses host verification

High 8.1

In plain English

A high-severity security flaw in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.8%top 44.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23curl8.23.0-r0ALPINE-CVE-2026-86410
Alpine:v3.24curl8.23.0-r0ALPINE-CVE-2026-86410
Debian:12curlno fix listedDEBIAN-CVE-2026-86410
Debian:13curlno fix listedDEBIAN-CVE-2026-86410
Debian:14curlno fix listedDEBIAN-CVE-2026-86410
Ubuntu:26.04:LTScurl8.18.0-1ubuntu2.8USN-8927-1
Ubuntu:26.04:LTScurl8.18.0-1ubuntu2.8UBUNTU-CVE-2026-86410
Ubuntu:26.10curl8.20.0-2ubuntu11.1USN-8927-2
Ubuntu:26.10curl8.20.0-2ubuntu11.1UBUNTU-CVE-2026-86410

Affected products (as reported)

VendorProductVersions
curl curl 8.22.0 – through 8.22.08.21.0 – through 8.21.08.20.0 – through 8.20.08.19.0 – through 8.19.08.18.0 – through 8.18.08.17.0 – through 8.17.08.16.0 – through 8.16.08.15.0 – through 8.15.0

Weakness: CWE-297 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References