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Vulnerability record · CVE-2023-42818 · published 27 September 2023

CVE-2023-42818: Fit2cloud jumpserver improper authentication vulnerability

Fit2cloud · Jumpserver

JumpServer is an open source bastion host. When users enable MFA and use a public key for authentication, the Koko SSH server does not verify the corresponding SSH private key. An attacker could exploit a vulnerability by utilizing a disclosed public key to attempt brute-force authentication against the SSH service This issue has been patched in versions 3.6.5 and 3.5.6. Users are advised to upgrade. There are no known workarounds for this issue.

9.8 CVSS 3.1 Critical EPSS 0.58% · top 54.4% CWE-287 · Improper authenticationCWE-307 · Improper restriction of authentication attempts
9.8CVSS 3.1 base score
0.58%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

JumpServer is an open source bastion host. When users enable MFA and use a public key for authentication, the Koko SSH server does not verify the corresponding SSH private key. An attacker could exploit a vulnerability by utilizing a disclosed public key to attempt brute-force authentication against the SSH service This issue has been patched in versions 3.6.5 and 3.5.6. Users are advised to upgrade. There are no known workarounds for this issue.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/jumpserver/jumpserver/security/advisories/GHSA-jv3c-27cv-w8jv ExploitVendor Advisory
https://www.sonarsource.com/blog/diving-into-jumpserver-attackers-gateway-to-internal-networks-1-2
https://github.com/jumpserver/jumpserver/security/advisories/GHSA-jv3c-27cv-w8jv ExploitVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.9CVE-2024-29202Fit2cloud jumpserver code injection vulnerabilityJumpServer is an open source bastion host and an operation and maintenance security audit system. Attackers can exploit a Jinja2 template injection v…EPSS 5.9%9.9CVE-2024-29201Fit2cloud jumpserver code injection vulnerabilityJumpServer is an open source bastion host and an operation and maintenance security audit system. Attackers can bypass the input validation mechanism…EPSS 5.9%9.9CVE-2023-43651Fit2cloud jumpserver code injection vulnerabilityJumpServer is an open source bastion host. An authenticated user can exploit a vulnerability in MongoDB sessions to execute arbitrary commands, leadi…EPSS 1.7%9.9CVE-2023-28110Fit2cloud jumpserver command injection vulnerabilityJumpserver is a popular open source bastion host, and Koko is a Jumpserver component that is the Go version of coco, refactoring coco's SSH/SFTP serv…EPSS 0.85%9.8CVE-2024-40629Fit2cloud jumpserver path traversal vulnerabilityJumpServer is an open-source Privileged Access Management (PAM) tool that provides DevOps and IT teams with on-demand and secure access to SSH, RDP, …EPSS 1.3%9.8CVE-2023-48193Fit2cloud jumpserver vulnerabilityInsecure Permissions vulnerability in JumpServer GPLv3 v.3.8.0 allows a remote attacker to execute arbitrary code via bypassing the command filtering…EPSS 2.0%9.1CVE-2024-40628Fit2cloud jumpserver path traversal vulnerabilityJumpServer is an open-source Privileged Access Management (PAM) tool that provides DevOps and IT teams with on-demand and secure access to SSH, RDP, …EPSS 0.86%9.1CVE-2023-43652Fit2cloud jumpserver missing authorization vulnerabilityJumpServer is an open source bastion host. As an unauthenticated user, it is possible to authenticate to the core API with a username and an SSH publ…EPSS 0.68%

Source: NIST National Vulnerability Database (record CVE-2023-42818), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.