# CVE-2026-31864: JumpServer has a Server-Side Template Injection Leading to RCE via YAML Rendering

> Administrative users can execute arbitrary code in JumpServer via Server-Side Template Injection in YAML rendering.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Mar 2026
- **Updated:** 13 Mar 2026
- **Also known as:** GHSA-qx8h-rx2j-j5wc

## What is CVE-2026-31864?

CVE-2026-31864 is a medium-severity code injection vulnerability in jumpserver, published on 13 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

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.

Weakness: CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine)

## Which versions are affected by CVE-2026-31864?

It affects 1 product.


Products: Fit2cloud Jumpserver.

## How do I fix CVE-2026-31864?

No fix has been published for CVE-2026-31864 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31864 being exploited?

There is no known exploitation of CVE-2026-31864 in the wild and no public exploit code.

## Other vulnerabilities in jumpserver

- [CVE-2024-40628](https://insights.sbomify.com/CVE-2024-40628/): Arbitrary File Read in Ansible Playbooks in Jumpserver (critical 10.0)
- [CVE-2024-40629](https://insights.sbomify.com/CVE-2024-40629/): Arbitrary File Write in Ansible Playbooks leads to RCE in Jumpserver (critical 10.0)
- [CVE-2024-29201](https://insights.sbomify.com/CVE-2024-29201/): JumpServer's insecure Ansible playbook validation leads to RCE in Celery (critical 10.0)
- [CVE-2024-29202](https://insights.sbomify.com/CVE-2024-29202/): JumpServer vulnerable to Jinja2 template injection in Ansible leads to RCE in Celery (critical 10.0)
- [CVE-2023-48193](https://insights.sbomify.com/CVE-2023-48193/): Security feature bypass in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31864 and fix it if it is affected.

What it is: CVE-2026-31864 is a medium-severity code injection vulnerability in jumpserver, published on 13 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-31864 in the wild and no public exploit code.

Affected product: jumpserver. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31864/ (Markdown: https://insights.sbomify.com/CVE-2026-31864/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31864
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31864
- OSV: https://osv.dev/vulnerability/CVE-2026-31864

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31864/
Summaries are generated and may contain mistakes; the official description above is the record.