CVE-2026-31864: JumpServer has a Server-Side Template Injection Leading to RCE via YAML Rendering
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 Software
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Frequently Asked Questions
What is the severity of CVE-2026-31864?
CVE-2026-31864 has a high severity rating due to its potential for remote code execution.
How do I fix CVE-2026-31864?
To fix CVE-2026-31864, update JumpServer to the latest version that addresses this vulnerability.
Who is affected by CVE-2026-31864?
CVE-2026-31864 affects users of JumpServer utilizing the Applet and VirtualApp upload functionality.
What type of vulnerability is CVE-2026-31864?
CVE-2026-31864 is classified as a Server-Side Template Injection vulnerability.
What can attackers do with CVE-2026-31864?
Attackers can exploit CVE-2026-31864 to achieve remote code execution on vulnerable JumpServer instances.