CVE-2026-31864CWE-1336

JumpServer has a Server-Side Template Injection Leading to RCE via YAML Rendering

Medium · published March 13, 2026

CVSS v3.1
6.8
EPSS
1%
Percentile
44.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00536 · 44.4th percentile
Weakness
CWE-1336 · Improper Neutralization of Special Elements Used in a Template Engine
Published
2026-03-13T19:22Z
EPSS history
Timeline
  • 13 MAR 19:22Z
    JumpServer has a Server-Side Template Injection Leading to RCE via YAML Rendering
    cvelistv5