CVE-2026-31864: JumpServer is an open source bastion host and an operation and maintenance security audit system. a Server-Side Template Injection (SSTI) vulnerability exists…

PriorityP340medium6.8CVSS 3.1

AVNACLPRHUIRSUCHIHAH

EPSS

0.35%

26.6th percentile

JumpServer is an open source bastion host and an operation and maintenance security audit system. a Server-Side Template Injection (SSTI) vulnerability exists in JumpServer's Applet and VirtualApp upload functionality. This vulnerability can only be exploited by users with administrative privileges (Application Applet Management or Virtual Application Management permissions). Attackers can exploit this vulnerability to execute arbitrary code within the JumpServer Core container. The vulnerability arises from unsafe use of Jinja2 template rendering when processing user-uploaded YAML configuration files. When a user uploads an Applet or VirtualApp ZIP package, the manifest.yml file is rendered through Jinja2 without sandbox restrictions, allowing template injection attacks.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
fit2cloud	jumpserver	< 3.10.22	3.10.22
fit2cloud	jumpserver	>= 4.0.0 < 4.10.16	4.10.16
jumpserver	jumpserver	< 3.10.22	3.10.22
jumpserver	jumpserver	—	—

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.