# CVE-2026-39424: MaxKB has CSV Injection in its Application Chat Export Functionality

> Attackers can inject malicious formulas into exported chat logs, leading to arbitrary code execution on administrators' workstations when opening the file.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Apr 2026
- **Updated:** 16 Apr 2026
- **Also known as:** GHSA-rr4r-7cj2-29vp

## What is CVE-2026-39424?

CVE-2026-39424 is a medium-severity code injection vulnerability in 1Panel-dev MaxKB, published on 14 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, the chat export feature is vulnerable to Improper Neutralization of Formula Elements in a CSV File. When an administrator exports the application chat history to an Excel file (.xlsx) via the /admin/api/workspace/{workspace_id}/application/{application_id}/chat/export endpoint, strings starting with formula characters are written directly without proper sanitization. Opening this file in spreadsheet applications like Microsoft Excel can lead to Arbitrary Code Execution (RCE) on the administrator's workstation via Dynamic Data Exchange (DDE). The issue is a variant of CVE-2025-4546, which fixed the exact same pattern in apps/dataset/serializers/document_serializers.py but missed the application chat export sink. This issue has been fixed in version 2.8.0.

Weakness: CWE-1236 (Improper Neutralization of Formula Elements in a CSV File)

## Which versions are affected by CVE-2026-39424?

It affects 1 product.


Products: Maxkb Maxkb.

## How do I fix CVE-2026-39424?

No fix has been published for CVE-2026-39424 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39424 being exploited?

There is no known exploitation of CVE-2026-39424 in the wild and no public exploit code.

## Other vulnerabilities in 1Panel-dev MaxKB

- [CVE-2025-66419](https://insights.sbomify.com/CVE-2025-66419/): MaxKB vulnerable to privilege escalation through sandbox bypass (high 8.8)
- [CVE-2025-66446](https://insights.sbomify.com/CVE-2025-66446/): MaxKB has a Python sandbox LD_PRELOAD bypass (high 8.8)
- [CVE-2025-64511](https://insights.sbomify.com/CVE-2025-64511/): MaxKB has SSRF in sandbox (high 7.4)
- [CVE-2026-39422](https://insights.sbomify.com/CVE-2026-39422/): MaxKB has Stored XSS via ChatHeadersMiddleware (medium 6.9)
- [CVE-2026-39423](https://insights.sbomify.com/CVE-2026-39423/): Stored XSS via Eval Injection in EchartsRander Component (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39424 and fix it if it is affected.

What it is: CVE-2026-39424 is a medium-severity code injection vulnerability in 1Panel-dev MaxKB, published on 14 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-39424 in the wild and no public exploit code.

Affected product: 1Panel-dev MaxKB. 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-2026-39424/ (Markdown: https://insights.sbomify.com/CVE-2026-39424/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39424
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39424
- OSV: https://osv.dev/vulnerability/CVE-2026-39424

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39424/
Summaries are generated and may contain mistakes; the official description above is the record.