CVE-2026-104126: Code Injection (CVSS 6)

Description

JumpServer is an open source bastion host and an operation and maintenance security audit system. Prior to 4.10.17-lts, JumpServer's Ansible-based automation rendering can evaluate attacker-controlled template expressions from users who have permission to create or execute affected automation tasks. Crafted content can invoke sensitive Ansible lookup behavior, including file, pipe, env, and password lookups, within the Ansible execution context, which can disclose files or environment values and may permit limited command execution under the privileges of the automation process. The issue does not provide unauthenticated access or direct access to unrelated JumpServer assets. This issue is fixed in version 4.10.17-lts.

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CVSS v3.1 Score

6.0

MEDIUM

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

EPSS — Exploit Prediction

0.0038

Probability of exploitation

0.30%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-94 CWE-94

References

Other References

https://github.com/jumpserver/jumpserver/commit/cc57ba0de5f6015746fae11cfc62402b11618e59 https://github.com/jumpserver/jumpserver/pull/16886 https://github.com/jumpserver/jumpserver/releases/tag/v4.10.17 https://github.com/jumpserver/jumpserver/security/advisories/GHSA-gr5x-5c4h-867g

Frequently Asked Questions

What is CVE-2026-104126? +

JumpServer is an open source bastion host and an operation and maintenance security audit system. Prior to 4.10.17-lts, JumpServer's Ansible-based automation rendering can evaluate attacker-controlled template expressions from users who have permission to create or execute affected automation tasks. Crafted content can invoke sensitive Ansible lookup behavior, including file, pipe, env, and password lookups, within the Ansible execution context, which can disclose files or environment values and may permit limited command execution under the privileges of the automation process. The issue does not provide unauthenticated access or direct access to unrelated JumpServer assets. This issue is fixed in version 4.10.17-lts. It has a CVSS v3.1 base score of 6.0 (MEDIUM).

How severe is CVE-2026-104126? +

CVE-2026-104126 has a CVSS v3.1 score of 6.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0038, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-104126? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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