JumpServer CVE-2026-44845

Exploitation requires an active JumpServer account with administrator-level privileges and specifically the 'Applet Host management and deployment' permission assigned. The attacker must navigate the Applet Host creation or editing workflow and supply a malicious Jinja2 expression in the IP/Host field or Core Service Address field, and then initiate an Applet Host deployment action to cause Ansible to evaluate the expression. Exploitation is limited by the following factors: the account must hold the elevated Applet Host deployment permission (not a default user role); the attacker must actively trigger a deployment operation, meaning the injection is not passively evaluated; and the command executes as the JumpServer service account, whose privilege level on the host OS varies by deployment. No network-external unauthenticated attack path exists - access to the JumpServer administrative web interface with the correct role assignment is a hard prerequisite.

CVSS 6.7 with PR:H correctly reflects that exploitation is gated behind a high-privilege account with specific Applet Host deployment permissions, which substantially reduces the attack surface compared to unauthenticated or low-privilege flaws. However, the NVD-assigned I:L metric appears inconsistent with arbitrary command execution on the control node - writing files, installing backdoors, or pivoting to managed bastion targets all constitute high integrity impact; this metric warrants vendor clarification. No EPSS score was provided in the input data. The absence of both a CISA KEV entry and confirmed public POC code means there is no evidence of opportunistic or widespread exploitation at this time. Real-world priority is elevated in environments where multiple teams share JumpServer admin access or where role segregation is weak - a malicious or compromised admin with Applet Host permissions can silently compromise the entire bastion infrastructure. In strictly controlled single-admin deployments the practical risk is lower, but the potential lateral reach to all managed assets via the control node makes this a high-priority patch regardless of the moderate base score.

A JumpServer administrator with Applet Host deployment rights navigates to the Applet Host management interface and submits a crafted IP/Host value containing a Jinja2 payload such as a subprocess invocation or file-write expression. When the administrator then triggers deployment, Ansible parses the inventory data containing the injected field and evaluates the template expression in the context of the JumpServer service account, executing the embedded command on the control node. No public POC has been confirmed, but the injection surface is well-understood from the Ansible and Jinja2 SSTI class of vulnerabilities.