CVE-2026-86410

redirect to SFTP or SCP bypasses host verification

Published Oct 20, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed

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 Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

curl

unaffected

Version	Status	Constraints
`8.22.0`	affected	≤ 8.22.0
`8.21.0`	affected	≤ 8.21.0
`8.20.0`	affected	≤ 8.20.0
`8.19.0`	affected	≤ 8.19.0
`8.18.0`	affected	≤ 8.18.0
`8.17.0`	affected	≤ 8.17.0
`8.16.0`	affected	≤ 8.16.0
`8.15.0`	affected	≤ 8.15.0
`8.14.1`	affected	≤ 8.14.1
`8.14.0`	affected	≤ 8.14.0
`8.13.0`	affected	≤ 8.13.0
`8.12.1`	affected	≤ 8.12.1
`8.12.0`	affected	≤ 8.12.0
`8.11.1`	affected	≤ 8.11.1
`8.11.0`	affected	≤ 8.11.0
`8.10.1`	affected	≤ 8.10.1
`8.10.0`	affected	≤ 8.10.0
`8.9.1`	affected	≤ 8.9.1
`8.9.0`	affected	≤ 8.9.0
`8.8.0`	affected	≤ 8.8.0
`8.7.1`	affected	≤ 8.7.1
`8.7.0`	affected	≤ 8.7.0
`8.6.0`	affected	≤ 8.6.0
`8.5.0`	affected	≤ 8.5.0
`8.4.0`	affected	≤ 8.4.0
`8.3.0`	affected	≤ 8.3.0
`8.2.1`	affected	≤ 8.2.1
`8.2.0`	affected	≤ 8.2.0
`8.1.2`	affected	≤ 8.1.2
`8.1.1`	affected	≤ 8.1.1
`8.1.0`	affected	≤ 8.1.0
`8.0.1`	affected	≤ 8.0.1
`8.0.0`	affected	≤ 8.0.0
`7.88.1`	affected	≤ 7.88.1
`7.88.0`	affected	≤ 7.88.0
`7.87.0`	affected	≤ 7.87.0
`7.86.0`	affected	≤ 7.86.0
`7.85.0`	affected	≤ 7.85.0
`7.84.0`	affected	≤ 7.84.0
`7.83.1`	affected	≤ 7.83.1
`7.83.0`	affected	≤ 7.83.0
`7.82.0`	affected	≤ 7.82.0
`7.81.0`	affected	≤ 7.81.0

No data.

Package	CPE	Advisory	Released Date
Red Hat Hardened Images
curl-main-8.23.0-0.1.hum1	cpe:/a:redhat:hummingbird:1	RHSA-2026:82895	2026-10-14T00:00:00Z

Vendor Product Versions

Curl

Version	Status	Scheme	Platform
`—`	affected	—	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Ubuntu USN	USN-8927-1	curl vulnerabilities
Ubuntu USN	USN-8927-2	curl vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.766% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact total

References

Link	Providers
https://curl.se/docs/CVE-2026-86410.html
https://curl.se/docs/CVE-2026-86410.json
https://hackerone.com/reports/3973176
https://nvd.nist.gov/vuln/detail/CVE-2026-86410
https://www.cve.org/CVERecord?id=CVE-2026-86410

History

Oct 31, 2026 10:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Oct 29, 2026 7:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics	cvssV3_1 `{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N'}`	cvssV3_1 `{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}`

Oct 20, 2026 8:15 PM Description updated. Title updated. Added references View changes

Type	Values Removed	Values Added
Description	A flaw was found in the curl command-line tool. When configured to follow redirects to Secure File Transfer Protocol (SFTP) or Secure Copy Protocol (SCP) destinations, curl fails to apply user-specified Secure Shell (SSH) host verification settings. A malicious server can exploit this flaw by redirecting requests to an untrusted server, causing the connection to proceed without validating the remote host's identity. This failure can enable an attacker to intercept communications, leading to sensitive information disclosure.	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.
Title	curl: curl: redirect to SFTP or SCP bypasses host verification	redirect to SFTP or SCP bypasses host verification
References		https://curl.se/docs/CVE-2026-86410.html https://curl.se/docs/CVE-2026-86410.json https://hackerone.com/reports/3973176

Oct 18, 2026 8:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Curl Curl curl
Vendors & Products		Curl Curl curl

Oct 16, 2026 12:30 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		A flaw was found in the curl command-line tool. When configured to follow redirects to Secure File Transfer Protocol (SFTP) or Secure Copy Protocol (SCP) destinations, curl fails to apply user-specified Secure Shell (SSH) host verification settings. A malicious server can exploit this flaw by redirecting requests to an untrusted server, causing the connection to proceed without validating the remote host's identity. This failure can enable an attacker to intercept communications, leading to sensitive information disclosure.
Title		curl: curl: redirect to SFTP or SCP bypasses host verification
First Time appeared		Redhat Redhat hummingbird
Weaknesses		CWE-297
CPEs		cpe:/a:redhat:hummingbird:1
Vendors & Products		Redhat Redhat hummingbird
References		https://nvd.nist.gov/vuln/detail/CVE-2026-86410 https://www.cve.org/CVERecord?id=CVE-2026-86410
Metrics	threat_severity `None`	cvssV3_1 `{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N'}` threat_severity `Low`