CVE-2026-18654
Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
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.
- Record
CVE-2026-18654- CVSS 4.0
- 6.9 Medium
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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-322
- Updated
- 2026-11-02
EUVDEUVD-2026-52415
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.
- Record
EUVD-2026-52415- CVSS 4.0
- 6.9 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hqvf-45jj-mccq
AWS CLI: Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
Summary
The AWS Command Line Interface (AWS CLI) is a unified tool to manage AWS services from the command line. An issue exists where the EMR SSH helper commands (aws emr ssh, aws emr socks, aws emr put, aws emr get) passed StrictHostKeyChecking=no to the underlying SSH client, disabling host key verification.
Impact
A network-positioned actor could perform a man-in-the-middle action to intercept SSH sessions and file transfers between the client and EMR cluster instances. Successful exploitation requires the actor to have network access on the path between the client machine and the EMR cluster endpoint. This could result in full visibility of commands executed, files transferred, and credentials passed over the SSH session.
Impacted versions: AWS CLI v1 <= 1.45.27, AWS CLI v2 <= 2.35.2
Patches
This issue has been addressed in AWS CLI v1 version 1.45.28 and AWS CLI v2 version 2.35.3. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There is no workaround. The insecure SSH option was hardcoded and could not be overridden by the user.
References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Acknowledgement
We would like to thank Ali Sunbul for collaborating on this issue through the coordinated vulnerability disclosure process.
- Record
GHSA-hqvf-45jj-mccq- CVSS 4.0
- 6.9 Medium
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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-322
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-18654- CVSS 4.0
- 6.9 Medium
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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-322
- Updated
- 2026-11-02
OSV
Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
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.
- Record
CVE-2026-18654- CVSS 4.0
- 6.9 Medium
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 - Weakness
- CWE-322
- Updated
- 2026-11-02
OSVGHSA-hqvf-45jj-mccq
AWS CLI: Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
Summary
The AWS Command Line Interface (AWS CLI) is a unified tool to manage AWS services from the command line. An issue exists where the EMR SSH helper commands (aws emr ssh, aws emr socks, aws emr put, aws emr get) passed StrictHostKeyChecking=no to the underlying SSH client, disabling host key verification.
Impact
A network-positioned actor could perform a man-in-the-middle action to intercept SSH sessions and file transfers between the client and EMR cluster instances. Successful exploitation requires the actor to have network access on the path between the client machine and the EMR cluster endpoint. This could result in full visibility of commands executed, files transferred, and credentials passed over the SSH session.
Impacted versions: AWS CLI v1 <= 1.45.27, AWS CLI v2 <= 2.35.2
Patches
This issue has been addressed in AWS CLI v1 version 1.45.28 and AWS CLI v2 version 2.35.3. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There is no workaround. The insecure SSH option was hardcoded and could not be overridden by the user.
References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Acknowledgement
We would like to thank Ali Sunbul for collaborating on this issue through the coordinated vulnerability disclosure process.
- Record
GHSA-hqvf-45jj-mccq- CVSS 4.0
- 6.9 Medium
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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-322
- Updated
- 2026-11-02
OSVPYSEC-2026-3627
AWS CLI: Disabled SSH host key verification in Amazon AWS CLI EMR helper commands
Summary
The AWS Command Line Interface (AWS CLI) is a unified tool to manage AWS services from the command line. An issue exists where the EMR SSH helper commands (aws emr ssh, aws emr socks, aws emr put, aws emr get) passed StrictHostKeyChecking=no to the underlying SSH client, disabling host key verification.
Impact
A network-positioned actor could perform a man-in-the-middle action to intercept SSH sessions and file transfers between the client and EMR cluster instances. Successful exploitation requires the actor to have network access on the path between the client machine and the EMR cluster endpoint. This could result in full visibility of commands executed, files transferred, and credentials passed over the SSH session.
Impacted versions: AWS CLI v1 <= 1.45.27, AWS CLI v2 <= 2.35.2
Patches
This issue has been addressed in AWS CLI v1 version 1.45.28 and AWS CLI v2 version 2.35.3. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There is no workaround. The insecure SSH option was hardcoded and could not be overridden by the user.
References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Acknowledgement
We would like to thank Ali Sunbul for collaborating on this issue through the coordinated vulnerability disclosure process.
- Record
PYSEC-2026-3627- CVSS 4.0
- 6.9 Medium
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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
awscliPyPI |
through 1.45.27 | 1.45.28 |
awscliPyPI |
before 1.45.28, plus listed versions 0.10.10.11.00.12.00.13.00.13.1 Show 45 moreShow less0.13.20.14.00.14.10.15.00.16.00.4.10.4.20.4.30.4.40.4.50.5.00.5.10.5.20.5.30.6.00.7.00.8.00.8.10.8.20.8.30.9.10.9.20.9.31.0.01.1.01.1.11.1.21.10.01.10.11.10.101.10.111.10.121.10.131.10.141.10.151.10.161.10.171.10.181.10.191.10.21.10.201.10.211.10.221.10.231.10.24 |
1.45.28 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-18654 is a medium vulnerability (CVSS 6.9) in Amazon Aws Command Line Interface, published August 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. Fixed in awscli 1.45.28.
References
github.com/aws/aws-cli/blob/develop/CHANGELOG.rst
aws.amazon.com/security/security-bulletins/2026-071-aws
nvd.nist.gov/vuln/detail/CVE-2026-18654
pypi.org/project/awscli
Left out here: 2,408 versions. The JSON record has them.