Disabled SSH host key verification in Amazon AWS CLI EMR helper commands

published 2026-08-03 3 mo ago modified 2026-10-23 16 d ago also GHSA-hqvf-45jj-mccq , PYSEC-2026-3627 , EUVD-2026-52415

cvss: 6.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits: 0; none known

Key exchange without entity authentication in the EMR SSH helper commands in Amazon AWS CLI before 1.45.28 and AWS CLI v2 before 2.35.3 might allow man-in-the-middle attackers to intercept SSHsessions and file transfers via network positioning between the client and the EMR cluster endpoint.

To remediate this issue, users should upgrade to AWS CLI v1 1.45.28 or later, or AWS CLI v2 2.35.3 or later.

Patch / fix

fixed in 2 links 2

pypi awscli 1.45.28
amazon aws_command_line_interface 1.45.28, 2.35.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-18654 updated 2026-11-05 cvss 6.8

aws-cli: AWS CLI: Information disclosure due to disabled SSH host key verification

Red Hat Enterprise Linux 7 awscli Red Hat Enterprise Linux 8 awscli Red Hat Enterprise Linux 9 awscli2, fence-virt, fence-virtd, fence-agents, fence-virtd-cpg, fence-virtd-tcp, +52 more Red Hat Enterprise Linux 10 awscli2
affected: workaround, no fix available “Fix deferred”
Red Hat Hardened Images mariadb11.8
not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-08-04)

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
CNA	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
OSV	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
GitHub	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	awscli	<1.45.28	1.45.28

Affected products

AWS aws-cli

Classification

Weakness

CWE-322 Key Exchange without Entity Authentication

References

github.com /aws/aws-cli/blob/develop/CHANGELOG.rst
patch, release-notes, web
github.com /aws/aws-cli/blob/v2/CHANGELOG.rst
patch, release-notes, web
aws.amazon.com /security/security-bulletins/2026-071-aws/
vendor-advisory
github.com /aws/aws-cli/security/advisories/GHSA-hqvf-45jj-mccq
release-notes, web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-18654
advisory
aws.amazon.com /security/security-bulletins/2026-071-aws
web
github.com /aws/aws-cli
package
pypi.org /project/awscli
package
github.com /advisories/GHSA-hqvf-45jj-mccq
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary