# CVE-2026-3749: Bytedesk SVG File UploadRestService.java handleFileUpload unrestricted upload

> Remote attackers can upload malicious SVG files due to unrestricted upload in Bytedesk, potentially leading to code execution or other impacts.

- **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/E:P`)
- **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:** 8 Mar 2026
- **Updated:** 11 Mar 2026
- **Also known as:** GHSA-995q-rmr5-rrmg

## What is CVE-2026-3749?

CVE-2026-3749 is a medium-severity vulnerability in Bytedesk, published on 8 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A weakness has been identified in Bytedesk up to 1.3.9. This vulnerability affects the function handleFileUpload of the file source-code/src/main/java/com/bytedesk/core/upload/UploadRestService.java of the component SVG File Handler. Executing a manipulation can lead to unrestricted upload. The attack can be executed remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 1.4.5.1 is able to resolve this issue. This patch is called 975e39e4dd527596987559f56c5f9f973f64eff7. It is recommended to upgrade the affected component.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-3749?

It affects 1 product.


Products: Bytedesk Bytedesk.

## How do I fix CVE-2026-3749?

No fix has been published for CVE-2026-3749 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3749 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3749 exists.

## Other vulnerabilities in Bytedesk

- [CVE-2026-3748](https://insights.sbomify.com/CVE-2026-3748/): Bytedesk SVG File UploadRestController.java uploadFile unrestricted upload (medium 5.3)
- [CVE-2026-3788](https://insights.sbomify.com/CVE-2026-3788/): Bytedesk SpringAIOpenrouterRestController SpringAIOpenrouterRestService.java getModels server-side request forgery (medium 5.3)
- [CVE-2026-3789](https://insights.sbomify.com/CVE-2026-3789/): Bytedesk SpringAIGiteeRestController SpringAIGiteeRestService.java getModels server-side request forgery (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3749 and fix it if it is affected.

What it is: CVE-2026-3749 is a medium-severity vulnerability in Bytedesk, published on 8 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3749 exists.

Affected product: Bytedesk. 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-2026-3749/ (Markdown: https://insights.sbomify.com/CVE-2026-3749/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3749
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3749
- OSV: https://osv.dev/vulnerability/CVE-2026-3749

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3749/
Summaries are generated and may contain mistakes; the official description above is the record.